You can redact PDF documents for free using Inkfolio’s Redact tool — but the part most people miss is that the redaction needs to be “flattened” into the file, or the hidden text can still be recovered.
Who needs proper redaction
Law firms sharing discovery documents that contain privileged information
HR departments releasing personnel files with SSNs, salaries, or medical notes removed
Journalists and researchers protecting sources named in leaked or public-records documents
Businesses responding to FOIA or subpoena requests where certain sections are legally exempt
Redaction vs. deleting a page
It’s worth knowing the difference between redacting and simply deleting content. If an entire page or section is irrelevant, deleting it is often cleaner than redacting it — a deleted page leaves no trace at all, while a redacted page still shows that something was removed (a black box signals “information was here”). Redaction is the right tool when you need the rest of the page intact and only specific words, numbers, or lines need to disappear — like a name, a signature, or an account number within an otherwise shareable document. Deleting is better when the whole page adds nothing the reader needs.
What Inkfolio’s Redact tool does behind the scenes
When you draw a box and run the redaction, Inkfolio removes the underlying text from that region entirely and rebuilds the page so the black box is part of the page content itself — not a separate layer sitting on top. Because this processing happens locally in your browser, the original, unredacted version of your file never gets uploaded anywhere, even temporarily, while the tool works.
The redaction mistake almost everyone makes
A shocking number of “redacted” PDFs online aren’t actually redacted. If you just draw a black box over text in a PDF editor without flattening it, the original text is often still there underneath — selectable, copyable, and recoverable by anyone who opens the file in the right tool. This has caused real, embarrassing leaks: government documents, legal filings, and corporate reports have all been “redacted” this way and then had the black boxes stripped off by someone just selecting the text underneath.
Redacting multiple pages at once
If the same type of information appears across many pages — like an account number repeated on every page of a statement, or a signature block on every page of a contract — you don’t need to redact each page separately in most cases. Upload the full document once, then mark the sensitive area on each relevant page before running the tool. Inkfolio applies the flattening step to the entire file in one pass, so a 20-page document with repeated sensitive fields takes the same one-time process as a single page, just with more boxes drawn.
What “flattening” actually means
Flattening merges the redaction box permanently into the page image itself, rather than layering it as a separate object on top of the text. Once flattened, there’s no text underneath to recover — the black box isn’t hiding the content, it has replaced it.
How to redact properly in Inkfolio
- Go to Inkfolio’s Redact tool
- Upload your PDF
- Draw boxes over the sections you want to remove
- Run the redaction — Inkfolio flattens it automatically, so there’s no extra step to remember
- Download the redacted file
Because this happens in your browser, the original (unredacted) file also never gets uploaded anywhere, which matters if the sensitive content is the whole reason you’re redacting it in the first place.
When you’d need this
- Sharing a contract with one clause removed
- Sending a document with personal ID numbers hidden
- Publishing a report with internal names or figures blacked out
Try it
Redact your files here— free, flattened automatically, nothing uploaded to a server.
