How we test, and when a page’s date changes
This page is the working rulebook behind product copy and field notes. It is not a laboratory accreditation and it does not replace official platform documentation.
Last reviewed 17 September 2026
Source priority
When a claim can collide with marketing language, we prefer evidence in this order:
- Primary documentation: official platform help, API docs, standards (C2PA, EXIF, ISO-BMFF), and model cards.
- Direct observation: behavior we can reproduce from a file in a current browser, or from the tool’s own output.
- Attributed third-party measurements: a named benchmark with version preserved.
- Community reports: useful, but labeled anecdotal until we can reproduce them.
Browser and format support
Metadata Cleaner accepts JPG, JPEG, PNG, WEBP, MP4 and MOV with a parseable ISO-BMFF/QuickTime box structure. HEIC/HEIF is not implemented. Safari, Chrome, Firefox and Edge are in scope for the cleaner’s Canvas / FileReader path; very large 4K masters can still exhaust a tab.
Local OCR uses Tesseract.js in the browser with English, Simplified Chinese, Traditional Chinese and Japanese. The Auto option does not detect script; it falls back to English.
Video Compressor requires WebCodecs. There is no WASM fallback. Hardware acceleration is preferred when the browser exposes it; we do not claim a specific encoder was used unless the browser says so.
PDF Toolkit copies page objects for merge/split/extract/reorder/rotate/remove where pdf-lib allows. PDF → Images is a rasterizing path and is labeled as such. Encrypted PDFs are not cracked.
Provenance evidence grades
The AI Image Origin Detector separates local inspection from optional official OpenAI verification.
- Trusted positive — an official OpenAI C2PA/SynthID result after the user chose to verify, or a structurally present C2PA/JUMBF packet the local inspector can show. Still not a statement about pixels.
- Useful clue — EXIF, XMP, PNG text, software tags, filenames. Easy to strip or rewrite.
- Missing / inconclusive — this scan did not find the field. Absence is not a human-origin proof. Screenshots and social recompression often destroy file-level credentials.
OCR accuracy
OCR quality depends on resolution, compression, language choice, and layout. Receipt totals, handwritten notes, and tiny UI type fail often. We do not publish a single “accuracy %” for marketing.
Searchable PDF export overlays Tesseract word boxes. Force OCR on a native-text PDF can leave both the original text layer and the OCR layer.
Video compression notes
Platform file-size limits (Discord, LINE, WhatsApp, and others) are copied from official docs when we cite a number, with a verification date on the article. We do not treat a competitor’s blog as the source of a limit.
Compression settings change size and quality; they do not control what a platform does after upload.
Privacy wording
A “no upload” sentence must match the default path of that tool. Optional OpenAI verification, remote URL fetch, and optional model download are disclosed on those screens and on About.
We do not log private filenames or file contents for analytics.
When dateModified changes
We update dateModified, article:modified_time and sitemap lastmod when the URL’s unique content materially changes: a platform limit, a product behavior, new evidence, or a substantial rewrite.
We do not bump those dates for CSS, header/footer chrome, analytics, or a one-letter spelling fix.
Sitemap lastmod is taken from this registry and from each article’s own dates. It is not the build timestamp and not the git checkout mtime.