.WEBP file signature
A WebP media file file begins with the bytes 52 49 46 46 ?? ?? ?? ?? 57 45 42 50 (RIFF....WEBP in ASCII) at the start of the file. The signature is the same whatever the file is named, which is why a renamed or extensionless WEBP file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 52 49 46 46 ?? ?? ?? ?? 57 45 42 50RIFF container; bytes 4 to 7 hold the file size. | RIFF....WEBP |
MIME type: image/webp · usual extensions: .webp
How to check a file's signature
Without installing anything: drop the file on our detector. It reads the bytes in your browser and shows the hex dump alongside the verdict; nothing is uploaded.
macOS and Linux (Terminal):
xxd -l 32 file.webp
file file.webpWindows (PowerShell):
Format-Hex -Path file.webp -Count 32If the bytes do not match
A file named .webp whose first bytes are something else is not a WEBP file. The common explanations are a wrong or deliberately misleading extension, a download that saved an HTML error page instead of the file, or a container such as ZIP wrapping the real content. The detector reports what the bytes say; the WEBP guide explains what a genuine file should contain.