You can redact sensitive information from a PDF 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.
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.
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
https://quirefile.com/ — free, flattened automatically, nothing uploaded to a server.