PDF Redaction (Secure) — Blackout or Blur in Your Browser
Redaction is the process of hiding sensitive information and preventing it from being recovered later.
Many people “redact” a PDF by drawing a black box on top of text, but the underlying text can often still be copied,
searched, or extracted. This tool takes a safer approach: when you click Apply & Download,
any page that contains a redaction is exported as a flattened, image-only page. That removes the
selectable text layer on those pages, which is what makes the output significantly harder to recover.
What this tool does (and the trade‑offs)
- Secure output: Redacted pages are flattened so hidden text cannot be selected or copied from those pages.
- No uploads: Processing happens in your browser.
- Trade‑off: Flattening may increase file size and removes search/copy on the redacted pages.
How to use it
- Load PDF to render pages and show thumbnails.
- Choose a mode: Draw Box for signatures/images, or Click Text/Drag Text for quick blocks.
- Select a style: Blackout (standard) or Blur (keeps layout feeling “natural”).
- Use Undo to remove the last redaction.
- Click Apply & Download. Only pages with redactions are flattened; other pages stay unchanged.
Blackout vs Blur
Blackout is the most widely accepted redaction style (legal, academic, government).
Blur is useful when you want to hide data while keeping the page visually readable,
but it should still be treated as sensitive — if your blur is too weak, someone may guess the content.
If it’s high‑risk (IDs, bank data, medical info), prefer Blackout.
Verification checklist (do this before sending)
- Open the exported PDF and try to select/copy text inside redacted regions (it should not work on flattened pages).
- Try a quick search for a redacted name/number in your PDF viewer.
- If you must keep the document searchable, consider splitting: keep a public (redacted/flattened) version and a private original.
- For privacy, remove metadata too (author/software/location) using the metadata guide.
Common use cases
- Scholarship / university portals: hide student IDs, addresses, signatures.
- Visa / embassy: hide passport numbers, booking references, payment details.
- Work documents: hide client names, invoice totals, internal notes.
Tip: keep redactions slightly larger than the text
Text in PDFs can be segmented into small glyph runs. A tight box can miss parts of a character, especially at low zoom.
Redact with a small margin around the sensitive content and zoom in to confirm you covered everything.
Need other PDF cleanup steps? Use Delete Pages to remove unnecessary pages,
Reorder PDF to fix page order, or Compress PDF if a portal rejects the file size.