.RTF file signature
A Rich Text Format document file begins with the bytes 7B 5C 72 74 66 31 ({\rtf1 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 RTF file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 7B 5C 72 74 66 31 | {\rtf1 |
MIME type: application/rtf · usual extensions: .rtf
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.rtf
file file.rtfWindows (PowerShell):
Format-Hex -Path file.rtf -Count 32If the bytes do not match
A file named .rtf whose first bytes are something else is not a RTF 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 RTF guide explains what a genuine file should contain.