.OGG file signature
A Ogg data file begins with the bytes 4F 67 67 53 (OggS 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 OGG file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 4F 67 67 53Every page starts with OggS; the first page reveals the codec (vorbis, OpusHead, FLAC). | OggS |
MIME type: audio/ogg · usual extensions: .ogg
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.ogg
file file.oggWindows (PowerShell):
Format-Hex -Path file.ogg -Count 32If the bytes do not match
A file named .ogg whose first bytes are something else is not a OGG 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 OGG guide explains what a genuine file should contain.