All Tools
253 toolsCrypto(12)
TOTP Two-Factor Code Generator
Generate TOTP two-factor authentication codes online. Enter or randomly generate a Base32 secret and the tool shows the code for the current time window plus the previous and next ones, matching apps like Google Authenticator.
Password Strength Analyzer
Analyze password strength online. Type a password and see its strength rating (weak, fair, strong or very strong) in real time, along with concrete suggestions such as adding length, uppercase letters, digits or special characters.
HTTP Basic Auth Generator and Decoder
Generate and decode HTTP Basic Auth headers online. Enter a username and password to build a standard Authorization header, or paste an existing header to recover the username and password behind it.
Text Hash Calculator
Online text hash calculator that computes MD5, SHA-1, SHA-256 and SHA-512 digests for your input at once, with output in hexadecimal, Base64, Base64url or binary.
Bcrypt Hash Generator and Verifier (Demo)
Online bcrypt-style hash generator and verifier for learning purposes. Generate a simplified bcrypt-style hash from a password, verify a password against a hash, and generate random test passwords. For demonstration only, not for production password storage.
AES Text Encryption and Decryption
Online AES-GCM text encryption and decryption tool. Enter text and a key of at least 8 characters to encrypt, then decrypt with the same key. Built on the browser's native Web Crypto API and computed entirely locally.
Argon2 Hash Generator
Online Argon2 password hash generator supporting argon2i, argon2d and argon2id with adjustable memory, iteration and parallelism parameters, plus built-in verification. Output follows the PHC string format.
BIP39 Mnemonic Generator
Online BIP39 mnemonic generator producing 12-word or 24-word phrases from the standard BIP39 word list. Intended for learning and testing how wallet mnemonics work, explicitly not for storing real asset keys.
HMAC Generator
Online HMAC message authentication code generator. Enter a message and key, choose SHA-256, SHA-1, SHA-512 or MD5, and see the HMAC computed in real time for API request signing and message integrity checks.
AES Encryption Tool
Online AES encryption and decryption tool supporting AES-128, AES-192 and AES-256 across ECB, CBC, CTR and GCM modes, with PKCS7/PKCS5 or no padding and Base64 or Hex input and output.
RSA Key Pair Generator
Online RSA key pair generator built on the browser's native Web Crypto API. Supports 1024, 2048 and 4096-bit keys and produces public and private keys in PEM format, computed entirely locally with nothing uploaded.
Secure Random Generator
Cryptographically secure random generator using the browser's crypto.getRandomValues(). Produces random integers, floats, UUID v4 values and random strings with a configurable character set and length, all generated locally.
Converter(18)
Unix Timestamp Converter
Convert between Unix timestamps and human-readable date-times online, with automatic detection of second, millisecond, microsecond and nanosecond precision, worldwide time zones including daylight saving handling, Windows FILETIME and C# Ticks conversion, and quick date-range shortcuts.
Base32 Encoder and Decoder
Encode text to Base32 and decode it back in real time, using the RFC 4648 alphabet. Text is handled as UTF-8 bytes, so non-ASCII characters round-trip correctly.
CSV to Markdown Table
Convert CSV, TSV and other delimited data into Markdown tables instantly. Supports custom delimiters, header detection and per-column alignment, with live preview and HTML output.
SRT to VTT Subtitle Converter
Convert subtitles between SRT and WebVTT in both directions, handling timestamp separators, cue numbering and the WEBVTT header automatically, with errors reported down to the individual subtitle block.
Base58 Encoder and Decoder
Convert text to and from Base58 using the Bitcoin alphabet, which omits the easily confused characters 0, O, I and l.
JSON to YAML Converter
Convert JSON data to YAML online. Paste JSON and the equivalent YAML appears instantly, with support for objects, arrays and nested structures, making it handy for configuration file conversion.
YAML to JSON Converter
Convert YAML data to JSON online with a configurable indent width. Paste YAML and the formatted JSON appears instantly, useful for configuration file conversion.
JSON to TOML Converter
Convert JSON data to TOML online. Paste JSON and the corresponding TOML configuration text appears instantly, suited to writing and migrating files such as Rust's Cargo.toml and Python's pyproject.toml.
TOML to JSON Converter
Convert TOML configuration into JSON online. Paste content from Cargo.toml, pyproject.toml or any other TOML file and get the equivalent JSON text instantly, ready for tooling that only understands JSON.
JSON to XML Converter
Convert JSON data into XML online. Paste a JSON object and get the matching XML tag structure, with special characters escaped automatically for legacy system and SOAP integrations.
XML to JSON Converter
Convert XML documents into JSON online. Paste XML and get the equivalent JSON tree instantly, so data from legacy XML APIs can be handled with modern JSON tooling.
CSV to JSON Converter
Convert CSV data into a JSON array online. Paste your rows or upload a CSV file, pick the delimiter, choose whether the first row is a header, and copy or download the JSON result.
JSON to CSV Converter
Convert a JSON array of objects into CSV online. Paste your array, get comma-separated table text with the object keys as the header row, then copy it or download a .csv file.
Base64 File Converter
Convert any file to a Base64 string and back again in your browser. Drag in an image, PDF or other file to get its Base64 or Data URL, or paste Base64 to decode and download the original file.
Base64 String Encoder and Decoder
Encode text to Base64 and decode Base64 back to text in your browser, with correct UTF-8 handling for Chinese and other multi-byte characters and support for both standard and URL-safe Base64.
Number Base Converter
Convert a number between numeral systems online. Enter a value, choose its base, and see the binary, octal, decimal and hexadecimal forms at once, with support for any base from 2 to 36.
Integer Base Converter
Convert integers between numeral systems online. Pick a source and target base from binary, octal, decimal, hexadecimal or any custom base up to 36, with signed values and grouped digit output.
Color Format Converter
Convert colors between HEX, RGB, RGBA, HSL, HSLA, HSV and CMYK online. Type a color value or pick one with the color picker, and every other format updates instantly with a live preview swatch.
Web(38)
SQL Formatter
Format SQL statements online. The tool breaks a one-line query into readable lines by inserting a line break before keywords such as SELECT, FROM, WHERE, JOIN and ORDER BY, making long statements much easier to read.
Markdown to HTML Converter
Convert Markdown text to HTML online. Supports heading levels one to three, bold, italic and line breaks, with Markdown on the left, a live rendered preview on the right, a source view and one-click copying.
TOML to YAML Converter
Convert TOML configuration to YAML online. Paste TOML content such as a Cargo.toml or pyproject.toml snippet and the equivalent YAML text appears instantly, which is handy for migrating configuration formats.
YAML to TOML Converter
Convert YAML data to TOML online. Paste a YAML mapping and the equivalent TOML text appears instantly, which is useful when writing Cargo.toml, pyproject.toml or migrating configuration to TOML.
XML Formatter
Format XML online. Paste XML that has been squeezed onto one line or badly indented and the tool re-indents it by tag nesting level as you type, ideal for tidying API responses and configuration files.
YAML Formatter and Validator
Validate and format YAML online. The tool checks your YAML syntax as you type, reports parse errors, outputs a normalized version with consistent indentation, and offers a JSON view of the same data.
HTML WYSIWYG Editor
Edit rich text visually and export the HTML. The toolbar offers bold, italic, underline, strikethrough, headings, lists and links, and the generated HTML source updates live and can be copied with one click.
MIME Types Cheat Sheet
Look up MIME types online. The cheat sheet lists 33 common file extensions with their MIME types, supports searching by extension, MIME type or description, and copies any value with a single click.
JSON Diff Tool
Compare two JSON documents online. The tool walks every level recursively and lists added, removed and changed keys with their exact paths, treating arrays as single values, which suits API responses and configuration checks.
JSONL Viewer
View and inspect JSON Lines data online. Paste or upload a .jsonl file, parse it line by line, search the list on the left to find a record, and read the selected line as a collapsible, syntax-highlighted tree on the right, with unparsable lines flagged.
QR Code Decoder
Read QR codes online from uploaded images, clipboard screenshots or images embedded in an Excel list, then copy the decoded content or open it directly if it is a link.
Browser Feature Support Detector
Detect whether your current browser supports recent web standards such as WebGPU, View Transitions and CSS :has() using real runtime feature checks rather than User-Agent sniffing.
Flexbox Layout Generator
Configure flex-direction, justify-content, align-items, flex-wrap and gap visually, preview the layout live and copy the resulting CSS with one click.
CSS Gradient Generator
Build linear and radial CSS gradients visually with an adjustable angle and any number of color stops, previewing the result and copying the background code with one click.
CSS Grid Layout Generator
Configure the columns, rows, gaps and column template of a CSS Grid layout visually, preview the grid live and copy the generated CSS with one click.
URL Parser
Parse any URL online and break it down into protocol, host, path, query string, hash and origin, with every query parameter listed as a name and value pair in a table.
URL Encoder and Decoder
Percent-encode and decode URL text online. Convert special characters to %xx form with encodeURIComponent or encodeURI, decode encoded strings back, and handle Unicode characters correctly.
HTML Entity Encoder and Decoder
Escape and unescape HTML special characters online. Paste text on the left, pick encode or decode, and see the converted result on the right in real time, all processed in your browser.
HTML Minifier
Minify HTML code online. Paste your markup, choose options such as removing comments and collapsing whitespace, and get compressed HTML along with a before-and-after size comparison.
CSS Minifier
Minify CSS code online. Paste your stylesheet, pick a compression level, and get compact CSS with comments removed, shorthand properties merged and color values shortened.
JavaScript Minifier
Minify JavaScript code online. Paste your script, choose options such as removing comments and shortening variable names, and get compact code plus a compression ratio report.
Meta Tag Generator
Generate SEO meta tags online. Fill in the title, description, canonical URL, Open Graph image and Twitter Card details, and get complete meta tag HTML ready to paste into your page head.
Slug Generator
Turn any text into a URL-friendly slug online. Supports mixed Chinese and English input, a choice of hyphen or underscore separator, and lowercase or uppercase output, updated as you type.
User Agent Parser
Parse a User-Agent string online to identify the browser and version, operating system and version, device type (desktop, phone or tablet) and rendering engine, or read your own browser's UA in one click.
HTTP Status Code Cheat Sheet
A searchable reference of 22 common HTTP status codes with bilingual explanations, grouped from 1xx to 5xx and color coded by category, filterable by number or by keyword.
HTTP Headers Parser
Paste raw HTTP request or response headers and get every field broken out with its name, value, and an explanation of what it does, with security-related headers highlighted.
IP Address Lookup
Shows your own public IP automatically and looks up any IPv4 or IPv6 address to reveal its country, region, city, ISP, ASN, coordinates, and time zone.
IPv4 Subnet Calculator
Enter an IPv4 address with a CIDR prefix or a dotted-decimal mask and get the network address, broadcast address, usable host range, host count, and binary breakdown.
Port Scanner Simulator
A searchable reference of common TCP and UDP ports. Look up a port number or service name to see what runs there, which range it belongs to, and any security notes. It is a lookup table for learning and reference, not a tool that actually scans hosts.
WiFi QR Code Generator
Turn a WiFi network name and password into a scannable QR code so guests can join without typing anything. Supports WPA/WPA2, WEP, and open networks, and downloads as PNG.
QR Code Generator
Turn a URL, plain text, phone number, or email address into a QR code, with custom foreground and background colors, adjustable size, live preview, and high-resolution PNG download.
ETA Calculator
Enter how much of a task is done, the total amount, and the minutes spent so far, and get the completion percentage, throughput per minute, time remaining, and the clock time you should finish.
Git Command Cheat Sheet
A searchable list of 21 everyday Git commands with explanations. Filter by command name or by keyword, and click any entry to copy it to your clipboard.
Regex Tester
Test a JavaScript regular expression against sample text with live highlighting, showing every match, its character position, and any named capture groups.
Docker Run to Compose Converter
Paste a docker run command and get the equivalent docker-compose.yml service definition, with the image, container name, port mappings, volumes, environment variables, and restart policy detected automatically.
Nginx Config Formatter
Paste a messy or minified Nginx configuration and get it back with correct indentation, consistent braces and semicolons, and all comments preserved.
JWT Parser
Paste a JSON Web Token to decode its header and payload into readable JSON, and see whether the token has expired based on the exp claim. Decoding only, no signature verification.
JWT Generator
Build a signed JSON Web Token from a custom payload, an HMAC algorithm such as HS256, HS384 or HS512, and your own key, with optional expiry. Intended for development and testing, not for issuing production tokens.
Network(4)
Peer-to-Peer File Transfer (LAN and Internet)
Send files straight from one browser to another over WebRTC. The file travels peer to peer instead of through a server, and the two sides pair up with a short code.
DNS Record Lookup Command Builder
Pick a DNS record type and domain to generate dig/nslookup/host commands and online lookup links in one click, plus a 16-type DNS record reference table — the tool itself performs no live DNS lookups.
MAC Address Vendor Lookup
Look up the manufacturer behind a MAC address using the IEEE OUI database. Accepts colon, hyphen, and unseparated formats, supports batch lookups, and distinguishes local from globally unique addresses.
Random Port Number Generator
Generate random port numbers from the well-known, registered, dynamic, or a custom range. Produces multiple deduplicated ports at once and flags commonly occupied ports so you avoid conflicts.
Text(33)
Training Needs Assessment Form Generator
Generate a standardized training needs assessment form online. Fill in department and position, check training areas, set high/medium/low priorities, then copy or download the result as a TXT file. Built for HR annual training planning and department-level needs surveys.
Labor Contract Expiry Tracker
Enter employee name, contract start date and duration to get the expiry date, days remaining and a four-level alert (expired / within 30 days / within 90 days / normal). Supports single entry and batch paste, helping HR renew contracts on time.
Annual Review Template Generator
Pick performance dimensions and set weights to generate a complete performance review form with scoring tables, self-assessment, manager comments and an overall rating. Supports annual, semi-annual and quarterly cycles, with copy and TXT download.
HS Code Lookup Reference
A 2-digit HS chapter code reference covering 21 sections and 97 chapters, with category browsing and keyword search with highlighting — a practical first step for classifying cross-border products.
Product Listing Score Analyzer
Score your e-commerce listing across 9 weighted dimensions — title, keywords, images, bullets, description, A+ content, video and reviews — on a 100-point scale, with tailored improvement suggestions.
Random Group Generator
Split a list of names into random groups online. Enter names by hand, paste a whole roster, or import an Excel/CSV file, then divide by number of groups or by group size and copy or export the result as CSV.
Import/Export Document Checklist Generator
Select trade direction, mode of transport, destination country/region and product type to auto-generate a matching checklist of import/export documents and requirements, ready to copy.
AI Prompt Template Library
A library of 39 ready-to-use prompt templates across 9 categories - writing, coding, data analysis, translation, creativity, marketing, education, office work, and interviews - with variable filling and one-click copy.
AI Ethics Checklist Generator
Generate a structured AI ethics checklist by application type, region and risk level, covering data privacy, fairness, transparency, security, human oversight and content safety.
Meeting Agenda Generator
Generate a structured meeting agenda with an automatic timeline, participants and per-item durations, exportable as plain text or Markdown.
ASCII Code Converter
Convert text to ASCII character codes and back online, in decimal, hexadecimal, binary or octal. Both panes are editable, so encoding and decoding update live as you type.
SWOT Analysis Template Generator
Enter your analysis topic and list strengths, weaknesses, opportunities and threats, then generate a SWOT matrix report with SO, WO, ST and WT strategy suggestions.
ASCII Table Reference
Look up the decimal, hexadecimal, octal and binary code of every character from 0 to 255 online, with range tabs for printable, control and extended ASCII plus keyword search.
Risk Assessment Matrix Generator
Log risks with likelihood and impact levels, get scores and low/medium/high/critical ratings automatically, and generate a 5x5 risk matrix report.
Email Newsletter Template Builder
Build HTML email newsletters visually with header, text, image, CTA and footer blocks, and generate code that works in Outlook and Gmail, plus a plain text version.
SMART Goal Template Generator
Break a goal down along the five SMART dimensions and generate a structured goal statement plus an automatic checklist with a completion score.
Daily Weekly Report Template Generator
Generate daily, weekly or monthly work reports online. Add completed tasks, plans, issues and reflections, pick simple, standard or detailed layout, and copy the Markdown report with one click.
AI Image Prompt Builder
A categorized tag library for Stable Diffusion and Midjourney. Click tags for subject, style, quality, lighting, composition, color and artist, and the tool assembles an English prompt with optional weight syntax and a negative prompt.
Kanban Board Text Generator
Build a visual kanban board online with custom columns and WIP limits, move tasks between columns, then export the board as aligned plain text or Markdown checklists and copy it anywhere.
Email Subject Line Analyzer
Score any email subject line from 0-100 with a local rule engine: length, spam words, personalization, emoji and urgency dimensions, an A+ to F grade and concrete suggestions. Fully offline, nothing is uploaded.
PDF Page Count Estimator
Estimate how many pages a PDF will be before you write it: enter word count, images and table rows, then tune font size, paper size and line spacing to get a page range, estimated file size and a breakdown of page usage.
Chinese Company Name Generator
Generate Chinese company names by combining an industry word list, an optional city prefix and a company type suffix, covering technology, finance, trade, manufacturing, healthcare and culture.
Amazon Keyword Index Checker (Simulated Demo)
Enter an ASIN and a keyword list to generate simulated index status, ranking and search volume data for understanding how an index-check report is laid out — this is demo data, not real Amazon index information.
Text Diff Checker
Compare two blocks of text side by side with additions in green and deletions in red, character-level inline highlighting, an ignore-whitespace option, and a count of changed lines.
Text Line Sorter
Sort lines of text alphabetically, in reverse, or shuffle them randomly, with optional duplicate removal, blank-line filtering, case-insensitive ordering, and a line count.
Find and Replace Text
Replace text across a whole document at once using either plain text or a regular expression, with an optional case-sensitive match, an instant preview, and one-click copy.
Text Case Converter
Convert English text between UPPERCASE, lowercase, Title Case, camelCase, PascalCase, snake_case, and kebab-case, with live output and one-click copy.
L33t Speak Generator
Convert ordinary English text into L33t speak by swapping letters for lookalike digits and symbols, with light, medium, and heavy intensity levels, live preview, and one-click copy.
Text to Binary Converter
Convert text into 8-bit binary code and decode binary back into text, with support for Chinese and other UTF-8 multi-byte characters. Bytes are separated by spaces for easy reading.
Text to Unicode Converter
Convert text into Unicode escape sequences and decode them back, with a choice of \uXXXX, U+XXXX, or HTML entity output. Handles Chinese, emoji, and other supplementary-plane characters.
Unicode Character Lookup
Look up any Unicode character by pasting the character itself or a U+XXXX code point, and see its official name, category, code point value, and UTF-8 / UTF-16 encoded bytes.
Numeronym Generator
Turn long English words into numeronyms such as i18n or a11y by keeping the first and last letters and replacing the middle with the number of characters. Handles one word per line for batches.
String Obfuscator
Obfuscate a string with Base64 encoding, Unicode escaping, or character shifting to make it harder to read at a glance, and restore it again for the reversible modes. Obfuscation is not encryption.
Data(7)
Shift Schedule Generator
Enter employee names and shift types to auto-generate a multi-day rotating shift schedule with staggered rotation, copyable in one click.
Random Chinese Address Generator
Generate random mainland China addresses online. Pick one of 15 provinces or choose random, generate up to 50 addresses at a time and copy them with a click, for use as test or placeholder data.
Test Bank Card Number Generator
Generate Luhn-valid bank card numbers for development and testing, covering Visa, Mastercard, American Express and UnionPay prefixes. The numbers are randomly generated and are strictly for testing - they are not real cards and cannot be used for any real transaction.
Barcode Generator
Generate nine common 1D barcode formats online, including CODE128, EAN-13 and UPC-A, with adjustable bar width and height, an optional human-readable line, and SVG download.
JSON Formatter and Validator
Online JSON formatter and validator. Format JSON into readable indented text or minify it to a single line, with live syntax validation that reports the exact parsing error.
JSON Prettifier
Beautify or minify JSON, with support for relaxed JSON5 syntax such as comments, trailing commas, single-quoted strings, and unquoted keys. Output is always standard JSON.
JSON Minifier
Online JSON minifier that strips spaces, line breaks, and indentation to produce the smallest single-line JSON, then reports the size before and after along with the percentage saved.
Math(45)
Industry Salary Benchmark Lookup
Look up 25th/50th/75th percentile monthly and annual salary benchmarks by industry, city tier, and job level.
Annual Leave & Time-Off Balance Calculator
Calculates statutory paid annual leave by tenure, then combines company extra leave, days already taken, and overtime comp hours into a total remaining leave balance.
Recruitment Cost & ROI Calculator
Aggregates agency fees, job board fees, referral bonuses, plus HR and interviewer time cost into total and per-hire recruitment cost with a breakdown.
Employee Turnover Rate Calculator
Calculates employee turnover rate by month, quarter, or year, separates voluntary from involuntary departures, and gives an annualized health rating.
Headcount Planning Calculator
Estimate required headcount from annual business volume and per-capita output, compare it with current staffing to find the gap, and estimate labor cost with optional average salary and budget cap. Built for HR headcount planning and hiring proposals.
Compensation Structure Builder
Enter base salary, performance base, performance coefficient, allowance and bonus months to instantly see monthly pay, annual pay, year-end bonus, component ratios and an estimated social insurance deduction, making compensation plan design and comparison easy.
Multi-Currency Exchange Rate Calculator
A free exchange rate calculator for 10 major currencies used in cross-border e-commerce. Reference rates are built in and fully editable, with single and batch conversion plus automatic cross-rate calculation.
VAT Calculator
Online VAT calculator for converting between net and gross amounts in both directions, with built-in 13%, 9%, 6%, 5%, 3% and 1% rates, optional surtax calculation and a batch mode.
Social Insurance Base Calculator
Enter your monthly salary and city to calculate the social insurance contribution base, including floor and ceiling handling, then see employer and employee contributions for pension, medical, unemployment, work injury and maternity insurance plus the housing fund, with adjustable rates.
Marketplace Fee Comparison Calculator
Compare fees, net income and profit margins across Amazon, eBay, Etsy, Shopify, AliExpress, Shopee and Temu. Enter price and cost, pick platforms, and see the best option highlighted automatically.
China Income Tax & After-Tax Salary Calculator
Work out your monthly China individual income tax and take-home pay from gross salary, personal social insurance and housing fund contributions, and special additional deductions. It also compares the two legal ways of taxing an annual one-time bonus and recommends the cheaper one.
FBA Storage Fee Calculator
Estimate Amazon FBA monthly and long-term storage fees. Converts dimensions to cubic feet automatically, switches peak (Oct-Dec) and off-peak rates, supports multiple months and inch/cm, lb/kg units.
Cross-Border Returns Cost Calculator
Measure the real cost of cross-border returns: return shipping, handling, depreciation on resellable items, full loss on unsellable items and exchange-rate loss, plus the break-even return rate.
PPC ACoS Calculator
Crunch Amazon PPC numbers in one click: ACoS, ROAS, TACoS and break-even ACoS, with profit/loss judgment against your margin and a suggested target CPC to guide bids.
Product Sourcing Cost Breakdown Calculator
Break down the full cost chain of cross-border sourcing — factory price, domestic logistics, packaging, QC, freight, insurance, tariff, VAT, port fees and FBA inbound — into landed cost per unit with cost-share bars.
Temu Supplier Price Calculator
Price products for Temu supply: derive a suggested supply price from your target margin, estimate the platform markup from the retail price, compare against competitor supply prices and get a margin-level assessment.
Shopee Commission Calculator
Enter your selling price, cost, marketplace and category to estimate Shopee commission, transaction fees and campaign service fees, then see your net profit and margin.
Work Seniority Calculator
Add up multiple periods of employment to get your total work seniority in years, months and days, along with the statutory paid annual leave entitlement that goes with it under China's Regulations on Paid Annual Leave for Employees.
Lazada Fee Calculator
Enter your selling price, cost, weight, marketplace and category to estimate Lazada commission, payment fees and LGS logistics fees, including a cross-border surcharge, and see your net profit and margin.
Linux File Permission (chmod) Calculator
Tick the read, write and execute boxes for owner, group and others to generate the octal chmod code, the symbolic notation and the full chmod command; you can also type an octal code and have the checkboxes filled in for you.
TikTok Shop Commission Calculator
Enter your selling price, cost, site and influencer commission rate to estimate TikTok Shop platform commission, transaction fees and influencer fees, with an automatic comparison against self-broadcast selling.
Multi-Model Token Cost Comparison
Compare API costs across 20 mainstream LLMs by pasting text or entering token counts, with per-call, daily and monthly cost rankings to pick the most cost-effective model.
AI Image Resolution Calculator
Pick an AI image model and enter your image size to find the best supported resolution, covering SDXL, Midjourney, DALL-E 3, Flux and more, with scale or crop hints.
OpenAI Batch API Cost Estimator
Estimate the cost of OpenAI Batch API requests (about 50% off) versus the synchronous API, with manual input and JSONL file modes and built-in reference prices for major models.
Age Calculator
Calculate age online from a date of birth. The tool gives the exact age in years, months and days, plus the total number of days and weeks lived and how many days remain until the next birthday.
Decision Matrix Calculator
Define weighted criteria, score each option from 1 to 5, and get weighted totals with a clear ranking to support rational decisions.
Presentation Time Calculator
Set your total presentation time and per-segment durations, then get a timeline with start/end times and remaining or over-time warnings.
Workstation Energy Cost Calculator
Enter the devices on your workstation with power and daily usage, get daily, monthly and yearly electricity costs and carbon emissions, plus a laptop-vs-desktop comparison.
Procrastination Cost Calculator
Calculate how much delay really costs you. Enter planned start, actual start and completion times plus an optional hourly rate to see delay hours, money wasted, annualized loss and an efficiency index, with blunt feedback and practical tips.
Newsletter Unsubscribe Rate Calculator
Calculate delivery, open, click, unsubscribe and complaint rates for an email campaign and compare them with industry benchmarks for e-commerce, SaaS, media, B2B and education, with a health score and improvement suggestions.
Sample Size Calculator
Compute the minimum sample size for statistical surveys using the Cochran formula, with finite population correction, confidence level comparisons, full calculation steps and practical advice.
SLA Uptime Calculator
Enter an SLA percentage to instantly get the allowed downtime per year/month/week/day, or enter actual downtime to work backward to an uptime percentage — includes a standard SLA-tier reference table.
Bandwidth Transfer Time Calculator
Enter a file size, network bandwidth, and transfer efficiency percentage to instantly get theoretical and actual transfer time plus the effective data volume, with a comparison table across common bandwidth tiers.
Cloud Server Cost Estimator
Enter your cloud provider, instance configuration (vCPU/memory/disk/traffic), and payment model to estimate monthly cost for AWS, Alibaba Cloud, and Tencent Cloud using built-in reference pricing, with a cross-provider comparison — figures are estimates, not live quotes.
RAG Embedding Cost Estimator
Enter document size, chunking parameters, an embedding model, and expected query volume to estimate a RAG system's indexing embedding cost, vector storage size, and ongoing query cost, comparing the annual total across popular embedding models.
FX Hedging Cost Calculator
FX hedging cost calculator for cross-border e-commerce sellers: compare no hedge, forward contract and option hedge, compute settlement gains/losses and hedging cost.
Tmall Global Fee Calculator
Tmall Global seller fee calculator: enter sale price, category commission rate and other fees to compute platform deduction, seller revenue, gross profit per unit, gross margin and break-even price.
Ad Budget Allocation Calculator
Enter total budget and per-channel CPC, conversion rate, average order value and margin; the tool allocates budget by channel effectiveness and estimates orders and profit, with manual fine-tuning.
Competitor Price Monitor Simulator
Paste a competitor price history to get min/max/avg/latest price stats, fluctuation analysis and a trend chart, plus a suggested selling range based on your cost. Pure front-end simulation with no web scraping.
China Maternity Leave Calculator
Free maternity leave calculator based on 2026 policy in mainland China. Enter the delivery date and province to work out maternity leave days, paternity leave days and the exact start and end dates, covering all 31 provinces with support for normal delivery, difficult delivery and multiple births.
Interest Calculator
Online interest calculator with simple interest, compound interest and equal monthly installment modes, covering deposit returns, loan repayments and investment growth, with a period-by-period repayment schedule.
Math Expression Evaluator
Online math expression evaluator supporting arithmetic, Math.xxx() method calls, and built-in shorthand for trigonometric, logarithmic, and absolute-value functions, plus the pi and e constants.
Percentage Calculator
Online percentage calculator covering the three common cases: what B% of A is, what percentage a part is of a total, and the percentage change between two values.
Average Calculator
Calculate the arithmetic mean of a set of numbers, along with the sum, count, maximum, minimum, median, and mode. Numbers can be separated by commas, spaces, or line breaks.
Random Number Generator
Generate random numbers within a range you define, in any quantity, with optional no-repeat mode for draws and a decimal mode with a configurable number of decimal places.
Measurement(21)
International Shipping Time Estimator
Estimate cross-border shipping times across express, air, sea, rail and line shipping on major routes between 8 origin and 12 destination countries, with peak-season delays and latest arrival dates by business day.
Online Stopwatch
An online stopwatch accurate to the millisecond, with start, pause and resume, lap recording and reset. Each lap shows both the elapsed total and the gap since the previous lap.
Product Carbon Footprint Calculator
Enter product type, material, packaging, manufacturing energy use and transport mode to quickly estimate a per-unit carbon footprint using a simplified EEIO plus material-factor model — not a formal LCA report.
JavaScript Benchmark Builder
Compare the performance of two JavaScript snippets online. Paste code A and code B, run each of them repeatedly for a chosen duration, and see the operations per second (ops/s) plus which version is faster and by how much.
Device and Browser Information Viewer
See detailed information about your current device and browser online. The page detects your browser and operating system and shows screen resolution, color depth, device pixel ratio, viewport size, touch points, CPU core count and more.
Webcam Video Recorder
Record video from your webcam directly in the browser. The tool captures camera and microphone with a live preview, records with one click and lets you download the finished video file, with all processing done locally.
Keyboard Key Code Finder
Find the JavaScript key codes of any keyboard key online. Click the capture area and press a key to instantly see its key value, code value, numeric keyCode and the state of the Ctrl, Shift, Alt and Meta modifiers.
Angle Unit Converter
Convert between angle units online. Enter a value in degrees, radians, gradians, arcminutes, arcseconds, quadrants or compass points and the tool instantly lists the equivalent value in every other unit.
Area Unit Converter
Convert between 13 area units online, from square millimeters up to square kilometers, including ares, hectares, acres and the Chinese mu. Enter one value and every other unit is calculated in real time.
Conference Call Time Converter
Pick a base city and meeting time, instantly see local times across 23 major cities such as Beijing, New York, London and Tokyo, and find common working hours.
Desk Ergonomics Calculator
Enter your height and working posture to get ergonomic recommendations for seat, desk, monitor and armrest positions, with healthy office tips.
Multi-Timezone Office Status Board
See local time and work status for offices across China, Japan, the US, UK and more at a glance. Working, almost-off, off-work, weekend and late-night states are detected automatically with countdowns and overlapping online offices, plus custom-time lookup.
Typing Speed Calculator
Measure your typing speed online: paste finished text with a known duration, or run a real timed test against built-in reference passages. Get WPM and CPM with a skill level rating, plus typical WPM ranges by profession.
Screen Recording File Size Estimator
Estimate screen recording file size before you record: choose resolution, frame rate, duration, content type and codec to see compressed size, raw size, a codec comparison (H.264/H.265/AV1) and storage advice.
Online Countdown Timer
A simple countdown timer with hour, minute and second inputs, start, pause and reset controls, quick presets and an alarm when time is up.
Server Rack Unit (U) Calculator
Add devices with name, U height, quantity, and power draw to automatically calculate the number of racks needed, the multi-rack allocation plan, total power draw, and estimated heat output — supports 42U/45U/47U/48U rack sizes.
Temperature Converter
Convert between Celsius, Fahrenheit, and Kelvin in real time. Type in any one field and the other two update instantly, with the conversion formulas shown.
Length Converter
Convert between metric, imperial, and nautical length units in real time. Enter a value in any field and every other unit updates at once, with precision chosen to suit the magnitude.
Mass Converter
Convert between metric and imperial mass units in real time, from kilograms, grams, and milligrams to pounds, ounces, metric tons, and short tons. All units update at once.
Speed Converter
Convert between km/h, mph, m/s, knots, and Mach in real time. Enter a value in any field and every other unit updates instantly.
Volume Converter
Convert between metric and US customary volume units in real time, from liters, milliliters, and cubic meters to gallons, fluid ounces, pints, and quarts.
Dev(50)
Regular Expression Cheat Sheet
A quick reference of commonly used regular expressions covering 18 everyday cases such as email, phone number, URL, IP, ID card number and date, each with an explanation, plus keyword search and one-click copy.
LLM Temperature & Top-P Sampling Visualizer
An interactive visualization using 12 built-in mock token probabilities that shows how temperature and top-p (nucleus sampling) reshape an LLM's output distribution - a local simulation, not a real model call.
Text Embedding Similarity Playground
Enter one query sentence and up to 10 candidate sentences to compute and rank similarity scores using three lexical-overlap methods - Jaccard, cosine (bag-of-words), and simplified TF-IDF - a demo of the concept, not a real embedding model.
LangChain Prompt Template Builder
Visually build a LangChain ChatPromptTemplate with System/Human/AI messages, variable placeholders and few-shot examples, and generate copy-ready Python or JavaScript code.
Model Evaluation Metrics Explainer
Quick reference for ML and LLM evaluation metrics - BLEU, ROUGE, F1, pass@k, BERTScore and more - with formulas, ranges and use cases, plus an interactive confusion matrix calculator.
Vector Dimension Comparison
Compare vector dimensions, context length, MTEB scores and prices of mainstream embedding models, with filtering and sorting, plus storage estimation for millions of text chunks.
MCP Server Boilerplate Generator
Generate ready-to-use TypeScript or Python MCP server skeleton code from your server info and tool definitions, right in the browser.
WebAssembly Module Size Estimator
Estimate the min/typical/max size range of a WebAssembly module based on source language, compile target, optimization level, and selected feature modules — a heuristic estimate, not a real file analysis.
WebRTC STUN/TURN Config Builder
Visually add STUN/TURN servers and ICE options, then generate ready-to-use RTCConfiguration JavaScript code and a JSON config file.
GraphQL Subscription Builder
Visually define a GraphQL subscription's name, arguments, and return fields, and generate the subscription query plus WebSocket connection sample code — no real connection is made in the browser.
Edge Function Cold Start Estimator
Estimate cold-start/warm-start latency and TTFB for edge functions based on platform, bundle size, and dependency count, with a cross-platform comparison and optimization tips — based on typical public benchmark values.
WebGPU Compute Shader Demo
Browse full WGSL shader source and WebGPU JavaScript call code for matrix addition, dot product, and reduction sum, with a JavaScript-computed CPU reference result. Detects real WebGPU browser support but does not actually dispatch the shaders to a GPU.
HTMX Request Builder
Visually pick an HTMX request method, trigger event, target, and swap strategy, then generate ready-to-use HTML element markup with a live preview and an attribute reference table.
WASM Binary Format Parser
Paste WASM binary as hex or Base64, or upload a .wasm file, and get a real, local, in-browser parse of the module header, section list, import/export tables, and type signatures — instruction streams inside function bodies are not decoded.
Pyodide Script Runner Generator
Write Python code, pick the scientific packages you need, and generate a self-contained HTML file with Pyodide embedded. Opening that generated file runs your Python for real via Pyodide — this builder page itself does not execute Python.
gRPC Request Builder
Paste .proto content or manually enter a Service/RPC definition to generate a grpcurl command plus JavaScript, Python, and Go gRPC client call code.
LLM Token Counter
Estimate how many tokens a piece of text will use with LLMs such as GPT and Claude, and see how much of a 16K, 32K, 128K or 200K context window it fills. Everything is calculated locally in your browser.
LLM API Cost Calculator
Enter input and output token counts plus a daily call volume to estimate per-call and monthly API spend against a built-in reference price list covering GPT-4o, Claude 3.5 Sonnet, Gemini 1.5 and more. Prices are for reference only - always check the vendor's current pricing.
Prompt Template Variable Editor
Paste a prompt template containing {{variable}} placeholders and the tool extracts every variable, builds a form for them, previews the filled-in result live and copies the final prompt in one click.
JSON Schema Validator
Put a JSON Schema on the left and the JSON data to check on the right, and get live validation with the exact failing field path and reason. Includes a one-click OpenAI function calling example. It implements a common subset of keywords, not the full JSON Schema spec.
RAG Text Chunking Calculator
Paste a long document, set chunk size and overlap, and see it split locally by estimated token count, with the character count, estimated tokens and a content preview for every chunk - handy for tuning RAG chunking strategy.
Vector Similarity Calculator
Compute cosine similarity, Euclidean distance and dot product between two vectors, or rank a batch of candidate vectors against a query vector to simulate retrieval - useful for debugging embedding and RAG results.
File Backup Rotation Schedule
Generate a Grandfather-Father-Son backup rotation schedule with configurable daily, weekly, monthly and yearly retention. See backup counts, estimate storage needs and get media rotation advice, plus a 3-2-1 strategy reference.
OpenAPI and Swagger Spec Validator
Check the basic structure of an OpenAPI 3.x document (openapi, info, paths), browse the endpoints grouped by path, and catch common issues such as missing responses or duplicate operationIds. JSON input only - YAML is not parsed.
GraphQL Query Formatter
Format GraphQL query, mutation and subscription text with consistent indentation, or minify it to a single line. Syntax checking is limited to bracket-stack matching - this is not a full AST parser.
.env File Parser
Parse a .env file online, flag common problems such as duplicate keys, missing equals signs and unquoted values, mask secret-looking values, and export the result as a JSON object or shell export statements.
Semantic Version Calculator
An online semver calculator for bumping versions (major/minor/patch/prerelease), comparing two versions, and testing whether a version satisfies a ^ or ~ npm range, following the semver.org specification.
.gitignore Generator
Tick templates for Node.js, Python, Java, Go, Rust, macOS, Windows, Linux, VSCode, IntelliJ IDEA and Docker, and the tool merges and deduplicates them into a ready-to-download .gitignore file.
README Badge Generator
Generate shields.io badge Markdown or HTML online, covering custom text badges, license badges, version badges (including live npm lookups) and build status badges, with a live preview.
OpenAI Fine-tuning JSONL Validator
Validate JSONL datasets in the OpenAI fine-tuning chat format line by line, checking the messages structure, role validity and user/assistant completeness, and reporting sample counts with an estimated token total.
SQL Explain Plan Analyzer
Paste MySQL or PostgreSQL EXPLAIN JSON output and get a clean, tree-style execution plan with warnings for table scans, high-cost nodes and actionable tuning tips.
Regex Performance Tester
Run a regex for real in your browser with timing, match counts, and a static analysis that flags catastrophic backtracking patterns before they freeze your production code.
Prompt Injection Escaper
Escape and wrap untrusted text before embedding it in an LLM prompt, and flag common injection keywords, to reduce prompt injection risk. This is a mitigation, not a complete defense.
YAML Anchors and Aliases Explainer
Parse anchors (&name) and aliases (*name) in YAML, count definitions and references, expand everything into complete YAML, and compare original, expanded and side-by-side views.
Cron Expression Humanizer
Translate 5 or 6 field cron expressions into plain-language descriptions with next run times. Supports L, W, # and @daily presets, plus a visual builder that generates cron from options.
UUIDv7 Generator
Generate RFC 9562 compliant UUIDv7 values, decode the timestamp encoded inside any UUIDv7, and generate batches to compare the sortability of v7 against v4 side by side.
JWT Claim Visualizer
Decode a JWT's header, payload and signature locally, group claims into registered, public and private, and see expiry status, remaining validity and the iat/nbf/exp timeline at a glance.
Markdown Front Matter Parser
Parse the front matter at the top of Markdown files used by Hugo, Jekyll and Next.js, separating fields from body text and merging them back into a complete document after form editing. Uses a simplified YAML parser, not a full specification implementation.
Code Review Checklist Generator
Generate a code review checklist from programming language, project type and review dimensions. Items are rated critical, major or minor with explanations, and can be ticked off with counts.
API Doc Previewer
Fill in endpoints, parameters and response examples through forms, and instantly generate a Markdown API doc, an OpenAPI 3.0 YAML spec and a rendered preview. No coding needed.
JSON Query Builder
Build JSONPath queries visually with filter, slice and recursive search operators, get jq and other language equivalents, and preview matches against pasted JSON data.
SSL Certificate Expiry Check Script Generator
Generates OpenSSL commands, Bash batch scripts, and Python scripts for checking SSL certificate expiry from a domain list — the tool itself makes no network requests; you run the output locally.
Domain SSL/TLS Security Configuration Checklist
A 20-item manual SSL/TLS security self-audit checklist across certificates, protocols, cipher suites, HTTP security headers, and DNS security — each item ships with a suggested command; generates a graded report, but never scans your domain automatically.
Common Regex Patterns
A searchable cheat sheet of regular expressions for phone numbers, email addresses, ID numbers, dates, IP addresses and more, with a built-in tester.
CDN Cache Purge Command Generator
Pick a CDN provider (Alibaba Cloud, Tencent Cloud, Cloudflare, AWS, Azure, or generic) and operation type, enter a URL list, and generate curl commands plus Python/Node.js/CLI code in one click — all credentials are placeholders and no request is ever actually sent.
Country Calling Code Lookup
Look up international dialing codes and ISO country codes for countries and regions worldwide, searchable by name, ISO code or calling code.
CSS Animation Generator
Generate CSS keyframe animation code from eight presets — fade, slide, bounce, rotate, scale, shake, pulse and flip — with a live preview and one-click copy.
KV Cache Memory Estimator
Select a preset LLM or enter custom model parameters, along with precision, batch size, and sequence length, to estimate the GPU memory required for KV Cache, model weights, and activations, and check it against common GPUs.
IEEE 754 Floating Point Converter
Online IEEE 754 floating point converter supporting single precision (32-bit) and double precision (64-bit), converting between decimal, hexadecimal and binary with a visual breakdown of the sign, exponent and mantissa bits.
Cron Expression Parser
Parse a cron expression into a plain-language description and preview the next several run times. Supports the standard 5-field format and the 6-field extended format with seconds.
Text Tools(1)
Electronics(1)
Hardware Detection(15)
PCB Gerber Layer Reference Viewer
Lists the standard Gerber file layers required for 2/4/6/8-layer PCBs, marking required vs. optional files and naming conventions to help engineers verify fabrication packages.
Transmission Line Impedance Calculator
Calculates PCB microstrip and stripline characteristic impedance using IPC-2141 formulas, and compares the result against common 50/75/90/100Ω targets.
I2C Pull-up Resistor Calculator
Calculates a compliant I2C pull-up resistor range and recommended value based on bus speed mode (Standard/Fast/Fast-plus), supply voltage, and bus capacitance.
Heatsink Thermal Resistance Calculator
Calculates the required heatsink thermal resistance (Rθsa) from a device's maximum junction temperature, ambient temperature, power dissipation, and junction-to-case/case-to-sink resistances, with heatsink recommendations.
Op-Amp Gain Calculator
Calculates gain (in V/V and dB) and output voltage for five basic op-amp circuit configurations: non-inverting, inverting, differential, voltage follower, and non-inverting summing amplifier.
Buck-Boost Converter Design Calculator
Calculates duty cycle, minimum inductance, current ripple, peak current, and output capacitance for Buck, Boost, and Buck-Boost switching converter topologies.
Antenna Length Calculator
Calculates wavelength and physical antenna length for quarter-wave, half-wave, full-wave, and 5/8-wave antenna types from operating frequency, with velocity factor adjustment and common RF band presets.
ADC Resolution Calculator
Enter ADC bit depth and reference voltage to calculate LSB voltage, quantization error, and dynamic range (dB), with bidirectional conversion between input voltage and ADC reading.
PWM Duty Cycle Calculator
Supports two calculation modes — "frequency + duty cycle → timing" and "period + high time → duty cycle" — with optional MCU clock frequency input to compute PWM resolution in bits.
Fuse Selection Calculator
Recommends fuse current rating (nearest standard value), voltage rating, and fuse type based on load type, operating voltage, and normal current, using industry derating factors, with optional inrush I²t calculation.
Keyboard Tester
Online keyboard tester that highlights each key the moment you press it, so you can quickly check that every key on the keyboard responds. No software to install.
Microphone Test
Online microphone tester that checks whether your mic is working in one click, showing a live volume waveform and letting you record a short clip and play it back. No software to install.
Reaction Time Test
Online reaction speed test. Click as soon as the signal turns green to measure your visual reaction time in milliseconds, with support for repeated attempts and an automatic average.
Mouse Sensitivity Converter
Online mouse sensitivity converter for FPS games. Convert sensitivity between titles using DPI and eDPI so your aim feels identical when you switch games.
Web Serial Debugger
Online serial port debugging tool built on the Web Serial API. Connect to a serial device straight from the browser with no driver installation, send commands and watch incoming data in real time.
Image Tools(6)
Image Cropper
Crop images online by dragging a selection box, with common aspect ratio presets and pixel-precise adjustment. Everything runs locally in your browser with no upload.
Image Compressor
Compress images in bulk online with an adjustable quality slider and an optional longest-edge limit, compare the before and after file sizes at a glance, and download everything as a ZIP.
Image Format Converter
Convert images to PNG, JPEG, WebP or BMP in bulk online. Everything is processed locally in your browser with no upload.
Image Base64 Encoder for Vision Models
Encode an image into a Base64 data URI, estimate GPT-4o image token usage with OpenAI's published tile formula, and check reference image limits for GPT-4V, Claude 3 and Gemini vision models. Everything runs locally in your browser.
Base64 Image Preview and Converter
Preview a Base64 string as an image, or turn an uploaded image into Base64, with image dimensions and data length shown alongside the result.
Image Color Picker
Upload, drag or paste an image and click anywhere on it to sample that pixel's color, with HEX, RGB and HSL values ready to copy.
Calculators(2)
BMI Calculator
Calculate your body mass index from height and weight in either metric or imperial units, with live results showing your weight category and health advice.
Coin Flip Simulator
Flip a virtual coin online for a random heads or tails result, with a running tally of how many times each side has come up.