Check a file for a Laidline mark.

Image or audio, up to 20 MB. You get an answer in plain words, and the file is not kept.

This is a quick check. The full read of a mark is at the checker of the provider that made it.

Choose or drop a file PNG, JPEG or WebP; WAV, FLAC, MP3, M4A, Ogg Opus or AAC. Up to 20 MB.

Nothing is sent until you press it. Six checks a minute per address, 1,000 a day in all.

This checker needs JavaScript. Without it: pip install "laidline[image]", then laidline detect FILE.

How to read the answer.

The answer leads with one line on who the file points to. Anyone can write an issuer number into a mark, so a number on its own is a claim.

Confirmed: The issuer's own checker or records found its mark in this file.
Signed: Content Credentials signed with the certificate the directory lists for that issuer, and any watermark agrees.
Claimed: A watermark carries an issuer number and nothing confirms it. The issuer's own checker may confirm it.
Mismatch: A watermark claims one issuer number and the Content Credentials are signed by another issuer's certificate.
Shared: A Laidline mark from the shared key. It proves a Laidline mark and names no provider.
Nothing found: No mark and no credentials. Absence of a signal is not evidence that content is human-made.