Redact PDF - Frequently Asked Questions
Answers about using PDF Lab to mask sensitive data locally with no uploads.
Does the redact tool upload my PDF?
No. All processing occurs in your browser. Files never leave your device.
How do I apply redactions?
Open the PDF, draw redaction boxes over sensitive areas, then click "Apply & Download." Black boxes are burned into the new PDF you download.
Can hidden text be recovered after redaction?
The tool covers content with opaque rectangles. Reopen the downloaded PDF to verify the masked content is not readable or selectable.
Does it work on scanned PDFs?
Yes - redaction boxes cover the visible raster layer. For best results, zoom in and ensure the area you need is fully covered.
Is there a file size limit?
For smooth performance, use small to medium PDFs (try under ~50-80 MB). Very large files may render slowly in the browser.
What about annotations or comments?
Anything visible under the box is covered. If you need to mask annotations, draw over them as well.
Ready to redact? Open the Redact PDF tool.