.TTF file signature
A TrueType Font data file begins with the bytes 00 01 00 00 at the start of the file. The signature is the same whatever the file is named, which is why a renamed or extensionless TTF file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 00 01 00 00Apple fonts may use 74 72 75 65 (true); collections use 74 74 63 66 (ttcf). |
MIME type: font/ttf · usual extensions: .ttf
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.ttf
file file.ttfWindows (PowerShell):
Format-Hex -Path file.ttf -Count 32If the bytes do not match
A file named .ttf whose first bytes are something else is not a TTF 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 TTF guide explains what a genuine file should contain.