What OpenAI checks
For supported images, OpenAI returns separate C2PA and SynthID entries. A detected result is evidence of the recognized signal. A not-detected result means that signal was not found; it does not rule out AI generation or modification.
Supported image formats
The current OpenAI provenance endpoint supports PNG, JPEG, and WebP images. OpenAI documents a 50 MiB provider limit; this site uses a stricter 15 MiB limit.
Privacy and responsible use
OpenAI states that Content Provenance checks are not eligible for Zero Data Retention and warns against repeated checks used to reverse-engineer or evade a watermark. The checker on this site therefore requires separate consent, is rate-limited, and is not connected to remover outputs.
Review the official OpenAI Content Provenance guide or open our side-by-side checker page.