Prove a human made it.
Synthless checks a file for AI watermarks and content credentials, then lets you sign for it. Anyone can look up the result.
Drop a file to check it
Runs on your device; nothing is uploaded until you choose to.
Accepts jpg, png, webp, mp4, mov, mp3, wav, txt, md, pdf.
What we check
Content credentials. Many cameras and editing tools attach a signed record of how a file was made, using the C2PA standard. Synthless reads that record and shows you what it says — including when it declares that the file was generated by a model.
AI watermarks. Some generators embed an invisible marker in what they produce. Checks for SynthID and C2PA signals where available. Where no detector is available to us, the check says it could not look, rather than claiming nothing was found.
File hash and metadata. Synthless computes a SHA-256 hash of the exact bytes you chose, and reads what the file says about itself. The hash is what a verification ID is bound to: change one pixel and it no longer matches.
A file with no AI watermark is not proof it was made by a person. That is why Synthless also asks you to sign for it.
What a verdict means
Synthetic
An AI watermark or content credential was found. This file cannot carry the Synthless mark.
Proven real
Captured with the Synthless app and unchanged since. The hash matches the original capture.
No capture app has been released, so nothing can carry this verdict yet.
Declared human-made
No AI signal was found and the person who made it signed for it. If that turns out to be false, this ID will be revoked here, publicly.
A file that has never been through Synthless has no verdict at all. It is not marked, and it never gets a badge. A revoked ID keeps its page — see an example.
The mark can be revoked
Every verification ID can be revoked. If a signed declaration turns out to be false, that ID’s page turns red and stays public — it is not deleted, because a badge that quietly disappears tells nobody anything. The badge on the creator’s own site changes with it. Read the revocation policy.
Get told when it opens
Issuing IDs opens soon. Leave an email and I’ll tell you when.