.PS file signature
A PostScript document file begins with the bytes 25 21 50 53 (%!PS 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 POSTSCRIPT file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 25 21 50 53 | %!PS |
MIME type: application/postscript · usual extensions: .ps
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.ps
file file.psWindows (PowerShell):
Format-Hex -Path file.ps -Count 32If the bytes do not match
A file named .ps whose first bytes are something else is not a POSTSCRIPT 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 POSTSCRIPT guide explains what a genuine file should contain.