Binary File Viewer
Inspect any file's hexadecimal and text content locally, with byte statistics, printable ratio, Shannon entropy and common file type detection; only the first 64 KB is read.
FreeOnline Tool
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How to Use
Choose or drop a file to see its overview, statistics and paginated Hex/Text content immediately.
- Click the dashed area to choose a file, or drag a file onto it. The file is read locally in the browser and is not uploaded.
- Review the file name, total size, detected type and six statistics: analyzed bytes, printable ASCII, extended bytes, entropy, zero bytes and unique byte values.
- Switch between Hex and Text. Hex shows 16 bytes per row with an 8-digit hexadecimal offset, byte values and ASCII; Text shows non-printable bytes as
.. - Use Previous and Next to page through 512 bytes at a time, or enter a decimal offset (such as 1024) or hexadecimal offset (such as 0x400) in the jump field and press Enter.
- Click Copy Hex to copy the full hex dump of the analyzed data. Click Load Sample Data to view a built-in sample containing a PNG header, Chinese text and every byte value from 0x00 to 0xFF.
Files larger than 64 KB are read only up to byte 65536, and a “first 64 KB only” badge is shown. Statistics and copying use that analyzed portion, not the whole file.
Features
- Hex view: 16 bytes per row with uppercase hexadecimal offsets, two-digit uppercase byte values and an ASCII column; non-printable bytes appear as dots.
- Text view: shows printable ASCII per page and renders all other bytes as
.. - Statistics: analyzed byte count, printable ASCII ratio (0x20–0x7E), extended-byte ratio (above 0x7E), Shannon entropy in bits/byte (maximum 8.00), zero-byte count and percentage, and unique byte values.
- Detects PNG, JPEG, GIF, PDF, ZIP, GZIP, ELF, BMP, TIFF, WebP and MP3 by file signature; anything else is shown as unknown binary.
- Paging in 512-byte chunks with previous, next and offset jump. Jump accepts decimal, 0x-prefixed hexadecimal, and values containing commas or underscores.
- Copy the complete hex dump with offset, hex and ASCII columns in one click.
- The built-in sample includes a PNG signature, UTF-8 Chinese text and all 256 byte values from 0x00 to 0xFF.
- File reading, statistics and rendering all run locally; files are not uploaded.
Use Cases
Verify a file's real type
Inspect signature bytes to check whether an extension matches the actual format, such as confirming that a download is really PNG or ZIP.
Learn binary file formats
Use the sample and real files to see how headers, offsets and ASCII map to each other and understand the start of formats like PNG or PDF.
Spot compressed or encrypted data
Use entropy and byte distribution to judge whether data is plain text, compressed, or close to random encrypted content.
Debug corruption or garbled files
Inspect leading bytes, zero-byte ratio and printable characters to help identify truncation, padding or encoding problems.
FAQ
Why is only the first 64 KB analyzed?
To avoid freezing while reading and rendering large files, the tool reads at most 65536 bytes. If the file is larger, a “first 64 KB only” badge is shown, and all statistics, paging and copying cover that portion rather than the whole file.
What does the entropy value mean?
Entropy is calculated from byte frequencies in bits/byte. Values close to 8 indicate a near-random distribution, typical of compressed or encrypted data. An all-zero file has entropy 0, and plain text is usually well below 8.
How is the file type determined?
Only from signature bytes at the start of the file, such as 89 50 4E 47 for PNG, %PDF for PDF or PK for ZIP. Contents are not parsed, so an unrecognized or very short file is reported as unknown binary.
Which file types can be detected?
PNG, JPEG, GIF, PDF, ZIP, GZIP, ELF, BMP, TIFF, WebP and MP3 are currently detected. Other formats can still be viewed in Hex and analyzed; only the type label is unknown.
Which offset formats does the jump field accept?
Decimal (1024), 0x-prefixed hexadecimal (0x400), hexadecimal with letters, and values containing commas, underscores or spaces. Invalid formats show an error; offsets beyond the file are clamped to the last byte.
Are files uploaded?
No. Files are read through browser-local APIs, and the hex dump, statistics and copying all happen on your machine. Nothing is sent to a server.