| Format | Extension | Hex signature | Description |
|---|
Magic bytes (also called a file signature or magic number) are a short sequence of bytes at the very start of a file that identifies its format regardless of the file name or extension. Tools like the Unix "file" command, upload validators and forensic utilities read these bytes to detect the real type of a file. This page lists 40+ common formats with their hex signature, typical extension and a short description.
Type in the search box to filter by format name (like PNG), extension (like .zip) or the hex bytes themselves (like FFD8FF). This is handy when validating uploads, carving files from a disk image, or debugging why a file will not open. Everything runs locally in your browser.