.PNG file signature
A PNG image data file begins with the bytes 89 50 4E 47 0D 0A 1A 0A (.PNG.... 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 PNG file is still recognisable.
Signature
| Offset | Hex | ASCII |
|---|---|---|
| 0 | 89 50 4E 47 0D 0A 1A 0AThe CR LF and LF after the name detect text-mode transfer damage. | .PNG.... |
MIME type: image/png · usual extensions: .png
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.png
file file.pngWindows (PowerShell):
Format-Hex -Path file.png -Count 32If the bytes do not match
A file named .png whose first bytes are something else is not a PNG 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 PNG guide explains what a genuine file should contain.