OPTPDF · Security
Blacken a PDF region by raster redaction
Choose a rectangular area to blacken in rendered page pixels, then create a new image-only PDF. This destructive raster workflow sacrifices searchable text and accessibility. It has not completed independent security review or adversarial recovery testing, so do not treat it as certified redaction.
Creates an image-only PDF with the selected rectangle permanently painted black. Text, forms, links, signatures and accessibility tags are removed. Review every output page before sharing.
When this tool helps
- Prepare a review copy with one visible rectangular region blackened.
- Remove an identified page-image area when image-only output is acceptable.
Questions and practical limits
Is this the same as drawing a black rectangle over text?
No. This workflow blackens rendered pixels and rebuilds the PDF as page images. An ordinary overlay can leave underlying text available for extraction.
Can I rely on it for a highly sensitive disclosure?
Independent security review and adversarial recovery testing remain outstanding. For high-consequence material, use a reviewed redaction process and verify the complete output rather than assuming safety.