What Content Credentials record
A C2PA manifest is a signed bundle stored inside the file (a JUMBF box in JPEG APP11 segments, a caBX chunk in PNG, a C2PA chunk in WebP). It names the claim generator — the software that signed it — and lists assertions such as c2pa.created, c2pa.edited or c2pa.opened, often with a digital source type of trainedAlgorithmicMedia for AI output.
| Source | Typical C2PA behaviour |
|---|---|
| ChatGPT Images / OpenAI API | Signed manifest declaring AI generation |
| Adobe Firefly, Photoshop generative features | Signed manifest; edits recorded as actions |
| Microsoft Designer / Bing Image Creator | Signed manifest declaring AI generation |
| Leica, Sony, Nikon and other C2PA cameras | Capture manifest from the camera |
| Midjourney, Stable Diffusion, most local tools | Usually no C2PA; check IPTC fields or PNG text instead |
Detection vs. validation
This checker detects the manifest and summarises its readable content. It does not verify the cryptographic signature or the hash that binds it to the pixels. For a signed verdict — including “this file was modified after signing” — open the same file in Content Credentials Verify.
Why the manifest disappears
Most social platforms, messaging apps and older editors drop unknown metadata on upload or export. A missing manifest is therefore not evidence that an image is human-made. If you sell AI images, disclosure duties on Etsy, KDP or stock sites apply either way.
Questions
Is C2PA the same as an AI watermark?
No. C2PA is metadata attached to the file and can be removed. Invisible watermarks such as Google SynthID live in the pixels and need the vendor’s own detector.
Will stock agencies see the manifest?
They can read it, but Adobe Stock still requires you to tick its generative AI declaration at upload, and Shutterstock does not accept AI-generated contributor uploads at all. Do not rely on metadata alone.
Why does the claim generator look technical?
It is the software identifier written by the signer, for example a library name with a version. The issuer is the organisation that holds the signing certificate.
Does checking upload my file?
No. The manifest is read inside this browser tab.
Primary sources
- C2PA technical specification
- IPTC Digital Source Type vocabulary
- Content Credentials Verify (official signature check)
Formats, standards and upload limits checked on November 5, 2026.