PDF Redaction Check
Check whether a "redacted" PDF still contains selectable text underneath its black boxes.
PDF documents Heavy client-side (WASM) pdf.js text runs + rendered page mask
Tool preview
How to use it
- 01
Drop the PDF you are about to send.
- 02
The tool renders every page and maps the extractable text onto it.
- 03
Read which text runs still sit on dark pixels.
Limitations
- ! It compares visible pages with extractable text; text outside the page box or inside attachments is not checked.
- ! A page with no text layer (a scan) always passes — there is nothing to copy out.
- ! Photos of documents need OCR before this check means anything.
FAQ
How does a fake redaction happen?
Most editors draw a black rectangle on top of the page. The text is still in the content stream, so selecting the page or running pdftotext reveals it.
What should I do when it finds hits?
Run the file through the PDF redaction tool, which rasterises the pages and destroys the text layer instead of covering it.
Is the PDF uploaded?
No.
Files never leave your device
Processing happens in your browser using the File API, WebAssembly and Web Workers. There is no upload endpoint.
Technical details
- Processing
- Heavy client-side (WASM)
- Implementation
- pdf.js text runs + rendered page mask
- Category
- PDF documents
- Network requests
- None while processing