What the engine can establish
Whether supported metadata structures were found and removed; whether the cleaned file can be parsed again; and whether the encoded visual payload covered by the current proof matches.
Open product evidence · version 2026.07.11
Metadata claims should be testable.
Metadata Lab is the public support matrix and methodology behind metadata.click. It states which containers are handled, what the visual-payload proof actually proves, and where the browser engine deliberately stops.
Last reviewed July 11, 2026 · feature-level conformance, not a universal format claim
Current support
Four formats, with different safety boundaries.
- JPEG Inspect + clean EXIF/GPS, standard XMP and recognized provenance blocks; write rights XMP; verify encoded scan payload with SHA-256.
- PNG Inspect + clean supported EXIF/text/XMP/provenance chunks; write rights XMP; verify image-data chunk payload with SHA-256.
- WebP Inspect + clean supported EXIF/XMP/provenance and trailing RIFF data; verify encoded image/animation chunks with SHA-256. Rights writing is not yet available.
- DNG / ProRAW Inspect-only. Rewriting is disabled because RAW metadata can be rendering-critical.
Method
Inspect, transform, re-inspect, compare.
- Validate the file signature and parse supported segment, chunk or IFD structures within safety limits.
- Remove or rewrite only supported metadata structures; do not decode and redraw the image.
- Inspect the result again and report which supported blocks remain.
- Hash the encoded visual payload before and after cleaning and compare the SHA-256 values.
A matching payload hash proves that the encoded JPEG scan data, PNG image-data payload, or WebP image chunks used by this check did not change. It does not mean the whole file is byte-for-byte identical, and it does not authenticate the scene or creator.
What metadata cannot establish
Metadata absence cannot prove that an image is human-made, anonymous or safe to publish. Platform classifiers, durable watermarks and server-side history sit outside ordinary file metadata.
Standards & sources
Built around public specifications and explicit limits.
- CIPA Exif 2.32 specification
- W3C Portable Network Graphics specification
- Google WebP RIFF container documentation
- C2PA technical specifications
- Google Images metadata guidance
The downloadable support matrix is licensed under CC BY 4.0 so researchers and publishers can cite it with attribution and a version date.
Use the evidence, not a slogan
Clean a copy and keep your original.
Run the free browser tool, inspect the result, and treat the proof according to its stated scope.