Magic Bytes & Binary Header Doctor
Inspect file magic signatures, view raw hex/ASCII headers, and repair corrupted binary file headers client-side.
🔒 Processed entirely in your browser — nothing you enter here is ever uploaded.
The result appears on this page after you run the tool. Nothing you enter is uploaded.
Result
About this tool
Verify file integrity and identify spoofed file extensions. This utility reads the initial bytes of any uploaded file to determine its true MIME type.
The tool renders the first 128 bytes in a styled Hexadecimal and ASCII matrix, letting you inspect headers. It matches bytes against a library of signatures (e.g. `89 50 4E 47` for PNG).
If a file header is corrupted or truncated, the Header Doctor will repair the initial bytes for popular extensions and let you download a working file.
Example. A file whose first bytes are 89 50 4E 47 0D 0A 1A 0A is labeled PNG Image, and the hex grid shows those bytes.
Limit. Header repair overwrites only the signature prefix for a known type such as PNG, JPEG, or PDF, and leaves every later byte unchanged.