Free checker

Check a file for an AI marking

Drop a file to see whether it carries a Tellmark mark or any other C2PA content credential.

Your file is checked in your browser and never uploaded. To confirm a mark, the page sends us the mark number it reads and hashes of the image.

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AI-generated Tellmark

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2 December 2026 checklist

Describes technical measures. Not a legal assessment.

Article 50 of the EU AI Act has applied since 2 August 2026.
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Providers of AI systems that generate synthetic audio, image, video or text must embed machine-readable markings and provide a way to detect them. Standard editing and non-substantial alterations are exempt.
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Providers of AI systems already on the market before 2 August 2026 have until 2 December 2026 to add these markings.
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AI systems that talk to people must disclose that they are AI, unless that is already obvious.
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The AI Office's Code of Practice on Transparency of AI-Generated Content sets out label icons for AI-generated content.
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What this checker reads

It looks for two kinds of mark in a JPEG, PNG or WebP image, and reads both in your browser.

C2PA Content Credentials

A C2PA manifest is signed metadata that states how a file was made. The checker reports any manifest it finds, from any vendor, not only Tellmark's. For a file Tellmark marked, it shows who marked it and when, for example "Marked as AI-generated by Example on 11 October 2026". Another vendor's manifest is reported as exactly that, without being checked against that vendor's own records.

An invisible watermark

Tellmark also hides an invisible watermark in the pixels of each image it marks. Many platforms strip a file's metadata on upload. If the manifest is gone but the watermark survives, the checker can still find the original record and check that the image is the one that was marked. Why Content Credentials disappear explains why metadata gets lost.

What a result means

A mark found: the file carries a statement that it was made or changed by AI, signed by whoever marked it.
No mark found: the file carries no mark this checker can read. That does not show it was made by a person. It may come from a tool that does not mark, or its marks may have been removed.

The checker reports marks. It does not decide whether an unmarked file is AI-generated, and it is not a deepfake detector. What marking cannot do sets out the limits, and C2PA and invisible watermarks compares the two kinds of mark.

To add these marks to your own AI-generated images, see how to add C2PA Content Credentials in Python, or the guide to the 2 December 2026 deadline.

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