Gemini watermark detector
Check content for a Google provenance signal.
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About this check
Gemini and SynthID
Google applies SynthID watermarks across text, image, audio and video produced by its models. It is one of the most thoroughly deployed provenance schemes in use — but verifying it requires Google's own detector, which is not available as a public programmatic interface.
What that means here
The SynthID check reports 'Not verifiable' rather than guessing. The adapter is implemented against a normalised response shape: configuring an endpoint switches the check to live results without any other change.
What runs today
Everything that can be read locally: invisible characters in text, C2PA manifests and metadata declarations in files. For Gemini-generated images, a declared synthetic source type in the metadata is often present and will be reported.