URL Probe Detector
Probe HTTP/HTTPS URLs in your browser for reachability, status codes, and response times. Supports multiple rounds, concurrency, timeouts, and retries, plus Excel/CSV import and CSV/JSON reports. Cross-origin targets without CORS headers are marked CORS, not failed.
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How to Use
- Choose an input mode: batch text (one URL per line, also separated by tabs, semicolons, or commas), a single URL, or Excel/CSV import (.xlsx/.xls/.csv, all worksheets are read).
- Set probe rounds (1–1000), per-request timeout (1000–30000 ms), concurrency (1–20), and retry count (0–3).
- Click Start probing. The browser sends GET requests directly and shows progress.
- In the results table, review status codes, success rates, and average/min/max response times; click Details for each round, retry count, and error message.
- Filter by all-success, partial success, network failure, or CORS-restricted results, then copy results or export CSV/JSON.
Limits: up to 500 URLs; HTTP 4xx/5xx responses are not retried; when a cross-origin target does not return CORS headers the browser cannot read the status code, so the tool falls back to no-cors and marks the result CORS, which does not mean the endpoint is down; an HTTPS page cannot request HTTP URLs; results depend on your local network, proxy, VPN, and ad-blocking extensions.
Features
- Three input modes: batch text, single URL, and Excel/CSV import. Batch text accepts newlines, tabs, Chinese/English semicolons, and commas, and automatically deduplicates URLs and skips invalid entries.
- Excel/CSV parsing reads every worksheet, skips cells that do not look like URLs (such as headers), and removes duplicate URLs.
- Adjustable probing: rounds (1–1000), per-request timeout (1000–30000 ms), concurrency (1–20), and retries (0–3). Retries apply only to network failures or timeouts, never to HTTP 4xx/5xx responses.
- Per-URL summaries include success rate, success/HTTP-error/CORS/failure counts, average and min/max response times, with expandable per-round details.
- Filters cover all-success, partial success, network failure, and CORS-restricted results; summary cards show total URLs, reachable, unreachable, and overall success rate.
- Copy results as text, or export a UTF-8 BOM CSV (opens cleanly in Excel) or a JSON report.
- When a cross-origin read is blocked, the tool retries once in no-cors mode, which only proves that a response arrived, and explains the CORS limitation in the interface.
Use Cases
Batch API health checks
Paste multiple endpoint URLs to review status codes and response times at once and quickly identify unreachable or 5xx services.
Post-release URL availability checks
After shipping new pages or APIs, run multiple probe rounds to confirm success rates and average latency, then export CSV as a release record.
Import a URL list from Excel
Operations or QA teams import a link column from Excel, deduplicate automatically, and probe the whole list without copying URLs one by one.
Compare response times across environments
Probe the same endpoints in test, staging, and production to compare average, minimum, and maximum response times and investigate performance differences.
FAQ
Why does a result show only CORS?
The browser's same-origin policy requires a cross-origin target to return CORS headers such as Access-Control-Allow-Origin before the status code can be read. The tool falls back to a no-cors request, which can only prove that a response arrived, not whether it was 200, 404, or 500, so the result is labeled CORS. CORS restrictions do not mean the endpoint is down; verify with a server-side client, curl, or Postman, or enable CORS for this origin.
Which file formats are supported?
XLSX, XLS, and CSV. Excel files have all worksheets read; CSV supports quoted fields, escaped double quotes, and a BOM. Cells that do not look like URLs, such as headers, are skipped, and duplicate URLs are removed.
When does a failed request get retried?
Only network failures and timeouts are retried, up to the configured count with a maximum of 3. HTTP 4xx/5xx means a response was received, so it is not retried. Retries are applied per round for each URL.
How many URLs can be probed at once?
Up to 500 valid URLs per run. Each URL can be probed for 1–1000 rounds, with concurrency from 1 to 20 and a per-request timeout from 1000 to 30000 ms. Out-of-range values are clamped to the limits.
Why does probing an HTTP URL fail from an HTTPS page?
Requests from an HTTPS page to an HTTP URL are blocked as mixed content before they are sent, and usually appear as network failures. Test those URLs from a server-side client or command-line tool instead.
Can it send POST requests or custom headers?
No. The tool always uses GET, follows redirects, sets cache to no-store, and sends only an Accept header. It checks URL reachability and does not support custom methods, request bodies, or headers.