PDF Image Redaction Checker
Checks whether a black box drawn over an image in a PDF (a scanned ID, a photo, a signature) actually removed the original content — or just covered it visually while the image data stays fully embedded underneath. Most redaction checkers only look at the text layer; this looks at images specifically. Runs entirely in your browser.
Drop a PDF here, or click to choose a file
Why isn't a text-layer redaction checker enough?
Text-layer checkers (including popular free tools like Redactr) verify whether text is still extractable under a black box — but by their own documentation, they don't check embedded images: if the redacted content is a scanned ID, signature, or photo with a black rectangle drawn over it, the original image bytes are still fully present in the PDF file, and a text-only checker has nothing to flag. This tool checks specifically for that case.
How does it detect this?
It walks the PDF's page drawing instructions (via pdf.js) and tracks where each embedded image is placed and where each filled shape is drawn, in order. If a dark, filled shape is drawn after an image and overlaps a meaningful portion of it, that's the exact pattern of "draw a black box over a photo to redact it" — and it means the image is still in the file, just visually covered.
Does this tool upload my PDF anywhere?
No. The PDF is parsed entirely in your browser using the pdf.js library (loaded from a CDN once, as code — never sent your file). Nothing about the document you check ever leaves your device.
Need this in a script or CI check instead of a browser?
The same detection logic is also a small CLI/library:
npx github:diwaspoudell/pdf-image-redaction-checker
— see
github.com/diwaspoudell/pdf-image-redaction-checker.