Redact PDF

Before a document goes out, certain details often need to disappear — account numbers, addresses, names, salaries or other personal data. Redact PDF lets you black out the parts you want to hide, so you can share a document responsibly without exposing private information.

Proper redaction matters for legal disclosures, freedom-of-information responses and any time you must release a document while protecting the people and details mentioned in it.

This is the single most consequential misunderstanding in document handling, and it has produced a long series of public failures by law firms, government departments and news organisations.

PDF is a layered format. Drawing a filled rectangle over text with an annotation or drawing tool adds a new object on top of the text. The text underneath is untouched — still present in the file, still selectable, still extractable by copying and pasting, running text extraction, or simply deleting the rectangle. The document looks redacted and is not.

Real redaction removes the underlying content and then draws the marking, so the text ceases to exist in the file. That is what this tool does: upload your PDF, mark the areas to conceal, and download a document where the marked content has been removed rather than covered.

Never take any redaction tool's word for it, including this one. The test takes ten seconds and it is the only thing that actually confirms the outcome.

Open the redacted file, try to select the text where the marking sits, and paste it somewhere. If nothing comes out, the content is gone. Then search the document for a distinctive string you redacted — a surname, an account number — and confirm the search finds nothing.

Review the whole document at full size as well, not just the pages you worked on. Sensitive details repeat in places people forget: a name in a header or footer, an account number in a reference line, an address in a signature block, the same figure restated in a summary table at the end.

A perfectly redacted document can still give away what you removed, through information that is not on the page at all.

PDFs carry metadata: author name, original filename, the software used, creation and modification timestamps, and sometimes the full file path it was saved from — which can itself disclose a client name, a case reference or an internal project code. A carefully redacted disclosure with the filename 'Smith-settlement-CONFIDENTIAL-draft3.pdf' recorded inside it has not achieved a great deal.

Check and strip metadata as a separate step. It is not covered by redaction, and most tools will not do it for you automatically.

Be alert to inference too. Redacting a name but leaving a job title, a date and a department can identify someone as effectively as the name would have, and redacting some instances of a term while missing others tells the reader exactly what was removed.

Redaction is applied in your browser, so the document is never uploaded or stored. The logic here is worth stating directly: the entire purpose of the operation is to prevent specific information from reaching other people, and the pre-redaction file — the one that still contains every detail you are trying to protect — is the version that would have to be transmitted.

Uploading an unredacted document to a third-party server in order to redact it means the complete original has already been disclosed before the tool does anything. Processing locally removes that step from the equation entirely.