Redact a PDF: black out text permanently
Draw black boxes, click the words to hide, or let the tool find emails, phone numbers, IBANs and French social security numbers. The redacted information is really removed from the file, not just covered.
- Free
- True removal
- Automatic detection
- 100% private
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to redact a PDF
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Upload your PDF
Drag the document into the box above: it opens right in your browser, without being uploaded.
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Choose what to hide
Draw rectangles, click a word or a line, or search for a name and turn on the detectors (emails, IBANs, phone numbers…).
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Download the redacted PDF
Check the areas in the preview, then download: the affected pages are rebuilt without the hidden text.
Redaction that leaves nothing behind
Text truly removed
Every redacted page is recreated from its image: the text, annotations and hidden layers under the boxes disappear from the file.
Search and detectors
Search for a name across the whole document and find emails, phone numbers, IBANs, French social security numbers, card numbers and dates in one click.
Other text still copyable
Optionally, the rest of the page stays selectable and searchable: only the words touched by a box are removed from the text layer.
Nothing is uploaded
Everything is processed in your browser. Your confidential documents never go through a server.
Why a black rectangle isn't enough
Putting a black rectangle over a PDF with a regular editor only covers the text: it stays in the file. Anyone can select the area, copy and paste, or delete the rectangle to read what was hidden. Official documents have leaked exactly this way. Here, every page that contains a redacted area is rebuilt: the tool turns it into a high-resolution image, paints the boxes directly into that image, then replaces the original page. The text, fonts, comments and form fields on that page are not copied over. Pages without redactions stay identical to the original, with their text and sharpness intact.
Find personal data automatically
Before sending a pay stub, a contract or a document for an application, you often need to hide personal data. Type a name or a word, and every occurrence is found on every page, ignoring capitals and accents. The detectors also find email addresses, French and international phone numbers, IBANs (with the check digits verified), French social security numbers, card numbers (validated with the Luhn algorithm) and dates. Every match appears in a checklist, so you stay in control of what gets hidden. Search works on the PDF's text; for a scanned document, draw the areas by hand.
A clean file that stays usable
Redacted pages are rendered at 200 dots per inch (300 in high resolution), which stays sharp when printed. By default, the original text is put back as an invisible layer, except for words that touch a box: you can still copy and search the rest of the page. Uncheck the option if you prefer image-only pages. The document metadata (title, author, software used) is also erased, along with bookmarks, attachments and scripts, which could hold hidden information. To check the result, open the new PDF and search for the redacted word: it should no longer be found.
Frequently Asked Questions
Can redacted text be recovered?
No. The affected pages are rebuilt from an image with the boxes painted in: the original text of those pages isn't copied into the new file. Only words outside the boxes are put back as invisible text, if the option is checked.
How is this different from “Write on a PDF”?
Write on a PDF adds elements on top of the page without removing anything: a white rectangle hides the text on screen, but it stays in the file. Redaction truly deletes the information: use it for anything confidential.
Is my PDF uploaded to a server?
No. Reading, searching and rebuilding pages all happen in your browser. The file never leaves your device, which makes it suitable for sensitive documents (pay stubs, medical records, legal papers).
Why doesn't search find anything in my document?
Your PDF is probably a scan: it only contains images, with no text. In that case, draw the areas to hide with your mouse or finger; they'll be painted into the page the same way.
Can I redact in white instead of black?
Yes, choose white before downloading. The result is just as permanent, but the area blends into the page background: handy for removing a line without leaving a visible box.