How to Redact a PDF for Free (black boxes)
- Upload a PDF — processing stays in your browser; no account or server upload is required.
- When the page preview appears, click and drag on the preview image itself to draw rectangles over text or areas to black out—not beside it. Delete a mistake with the trash icon on that box; use Previous/Next for more pages.
- Use Clear all to start over, or Apply to burn solid black rectangles into a new PDF with pdf-lib.
- Open the downloaded file to verify coverage. For legal-grade removal of searchable text, follow your organization’s redaction policy.
FAQ
- Is my PDF uploaded?
- No. The file is read and written in your browser tab using pdf-lib; OmniPDF does not receive your document.
- Can someone search hidden text after export?
- Black rectangles cover content visually, but underlying text may still exist in the PDF. For regulated or legal workflows, use a certified redaction process.
- Does it work on mobile?
- Yes on modern mobile browsers, though precise dragging is easier with a mouse or stylus on larger screens.
Performance
Since OmniPDF processes files locally using your computer's power (WebAssembly), there is zero upload time. It is 5x faster than cloud-based converters for large files.