Four things get called an AI detector
A signed Content Credential, ordinary file metadata, a proprietary watermark, and a statistical image classifier answer different questions. They can agree, disagree, or be absent independently.
Signed provenance
C2PA Content Credentials bind a structured manifest to an asset. A validator can check whether the record is well formed, whether protected bytes changed, whether the signature is valid, and whether the signer chains to the configured trust list.
Generator and workflow metadata
PNG text, XMP, EXIF, and application-specific fields may contain a generator name, prompt, seed, model, or workflow graph. These details can be precise, but ordinary export and social platforms can remove them.
Invisible provider watermarks
A system such as SynthID can embed a signal into pixels. A text or metadata reader cannot reproduce a closed detector. The provider’s supported verifier is required.
Visual classifiers
A classifier estimates whether pixels resemble known generated images. Compression, edits, new model families, and unusual human artwork can change its error rate. A score is not file provenance.
How to read the result
| Result | What it establishes | What it does not establish |
|---|---|---|
| Trusted credential | A valid manifest signed through the configured trust list. | That every assertion is objectively true or that the picture is harmless. |
| Valid, untrusted | The structure, signature, and binding validated. | A public identity for the signer. |
| Generator metadata | The inspected file stores a named tool or workflow reference. | That every pixel came from that tool. |
| No supported evidence | No supported marker matched. | Human authorship or absence of a closed watermark. |
Why a negative result stays narrow
A screenshot can flatten metadata. An editor can export a new file. A platform can transcode an upload. A remote credential may require recovery technology this site does not control. The honest answer is therefore “not found in the supported layers,” not “human.”
A practical check before publishing
- Keep the original export.
- Run the local evidence check before uploading it anywhere.
- Review C2PA validation separately from ordinary metadata.
- If the question names a proprietary watermark, use that provider’s verifier.
- Save the JSON report with your project records.