Testing & editorial methodology

MetadataViewer.org is maintained by the site operator. We do not invent individual authors, reviewers, user quotes or credentials. Technical pages identify the behavior we actually test, distinguish detection from cryptographic verification, and link primary specifications or vendor documentation when a claim depends on an external standard.

How file-cleaning behavior is tested

• Byte-level parsers have automated positive, negative and preservation cases.
• Cleaning tests confirm targeted metadata disappears while unrelated structural data remains.
• Every release is built as production HTML and checked for canonical URLs, JSON-LD validity and sitemap consistency.
• High-risk paths are also tested through the browser: inspect a file, download the clean copy, then inspect the copy again.

C2PA tests include multi-part JPEG APP11/JUMBF data, unrelated APP11 segments and PNG caBX chunks. Release acceptance also uses image fixtures from the official contentauth/c2pa-rs project.

What a test result does not prove

Metadata is editable. A timestamp is not proof of authorship; a missing C2PA container is not proof that an image is camera-original; and container detection is not certificate or signature validation. Each tool page documents its format-specific limits and fallbacks.

Editorial source policy

Standards claims should cite the standards body or reference implementation. Platform instructions should cite the platform vendor. Open-source behavior should cite the project documentation. Time-sensitive statements are dated or removed when they cannot be kept current. Search performance is evaluated with Search Console data, while unavailable data is reported as unavailable rather than treated as zero.

Privacy and corrections

Local files are processed in the browser and are not uploaded to MetadataViewer.org. The YouTube URL tool is a documented exception: it sends the public video ID to a public metadata endpoint. To report a reproducible bug, an incorrect claim or a source that needs updating, email contact@metadataviewer.org with the page URL and a non-sensitive test case.