How to redact a PDF for free
Published October 27, 2026
To redact a PDF, the text has to be removed from the file, not just covered. A black rectangle drawn in a PDF viewer sits on top of the words, and anyone who copies that area or extracts the text gets them back. Free tools that remove the text do exist: Preview on a Mac, and several browser tools listed below. Whichever you use, check the finished file the way the person receiving it would. This is general information, not legal advice.
Removing text versus drawing a box
A PDF page is a list of drawing instructions: put these letters here, draw this line there. A comment, a highlight or a shape is a separate object laid over the page. When you draw a black box with a markup or shapes tool, the letters underneath are still in the list. On screen they look gone. Copy and paste, a search, a screen reader or a text extraction program still finds them. The guide on why black box redactions fail covers the ways this goes wrong.
A real redaction tool does one of two things. It deletes the letters from the page and draws the box in their place, or it turns the page into a picture with the box burned in, so there are no letters left to copy. The second method is simple and thorough, but a page that is a picture can no longer be searched or selected.
Free ways that remove the text
Each of these describes itself as removing the text, not covering it; we read their sites in October 2026, and in our own test RedactPDF.io removed what it marked.
| Tool | What is free | How it works | Where the file goes |
|---|---|---|---|
| Preview on a Mac | Built in. Apple's Preview guide lists the redaction tool from macOS Big Sur (version 11) on. | You select text. Apple says the redaction becomes permanent once you close the document. | Stays on your Mac |
| batesstamp.com | Free, no account | You draw boxes; every page is then rendered as a 300 DPI image with the boxes in it | Stays in your browser |
| letsgoPDF Smart Redact | Free, no account | Finds email addresses, phone numbers, Social Security numbers, card numbers and IBANs, then deletes the text | Stays in your browser |
| RedactPDF.io | Free, no account | Suggests names, email and street addresses, ID, phone and card numbers; you review them | Uploaded, encrypted, to its servers in the EU and deleted after download |
| RedactifyAI | Page 1 without signing up; 50 pages a month with a free account | Detects more than 40 kinds of personal data and removes the text | Uploaded to its servers in the US |
| AI-Redact | 4 pages without signing up | Automatic detection, and it reads scans | Uploaded to its servers |
There is also a do-it-yourself route: draw your boxes, turn each page into an image, and combine the images back into a PDF. It works, but nothing in the result can be searched or selected. Printing to PDF on its own is not the same thing. It usually keeps text as text, so the box becomes part of the page while the words under it stay in the file. More on Preview in redacting a PDF on iPhone or Mac.
How to check it worked
- Copy the area. Open the finished file, select across each black box, copy, and paste into a plain text editor. Anything that pastes is still in the file.
- Search for what you removed. Use the viewer's search for the first digits of the number, or for a name. A hit inside a black box means the text is still there.
- Look at the document properties. Title, Author, Subject and Keywords can carry a name or an account number that never appears on a page.
- Search the rest of the file. The number you boxed on page 1 may also be printed in a page header, on a check image or in a transfer description on page 4.
The free leak check does these in one pass. It extracts the text of every page, searches it for Social Security, account, routing and card numbers, dates of birth, email addresses and phone numbers, flags text hidden under boxes, and reads the metadata. It searches the whole file, so it also finds numbers nobody marked. Scanned pages without a text layer are flagged as not checked.
What the free tools leave to you
- Finding each number. Manual tools remove only what you mark. Automatic ones look for patterns, and formats vary: in our own test of one free tool on a sample file, Social Security numbers written without dashes or with spaces, and a routing number, were left readable. Review every page yourself.
- Keeping the last four digits. Federal court rules allow the last four digits of a Social Security or account number to stay in a filing, and some state rules allow less. See redacting SSNs and account numbers in court filings.
- Searchable pages. A tool that turns every page into an image makes the whole file unsearchable, including pages with nothing removed.
- Scans. A scanned page is a picture. A tool without OCR cannot read it, so it cannot find a number on it.
- Bates numbers. Documents handed to the other side in a lawsuit are often Bates-numbered as well. See what Bates numbering is.
Which free route fits
For one bank statement going to a landlord, Preview or any of the browser tools above is usually enough, followed by a check; see redacting a bank statement. For a court filing, the court's rules say which part of a number may stay, and a lawyer or the court's self-help center can say what applies to your case. For a large set of documents in a production, free tools work page by page and file by file, and that is where the hours go. The tools comparison sets them side by side.
BatesNumbering.app looks for Social Security, tax ID, account, routing and card numbers across a whole set of PDFs in your browser, lets you keep the last four digits, burns the boxes into only the pages that have them, and runs the leak check on the output; the first 10 pages are free.
Common questions
Can you redact a PDF for free?
Yes. Preview on a Mac has a redaction tool, and free browser tools such as batesstamp.com and letsgoPDF say they remove text rather than cover it. Check the finished file by copying each redacted area and searching for what you removed.
Does drawing a black box redact a PDF?
No. A box drawn with a markup or shapes tool sits on top of the text, which stays in the file and can be copied or extracted. Real redaction deletes the text or turns the page into an image with the box burned in.
Is Adobe Acrobat's redaction tool free?
No. Adobe lists redaction among the features Acrobat Pro adds over Acrobat Standard, and Acrobat Pro was $19.99 a month on an annual plan on Adobe's pricing page in October 2026.
How do I know if a PDF redaction worked?
Select across each redacted area, copy it and paste it into a text editor, then search the file for part of what you removed and read the document properties. A free leak check that reads the whole file does the same in one pass.
Redact and Bates-number a set of PDFs in one pass →Or check a PDF for numbers left in it, free →
More guides: What is Bates numbering · Bates numbering without Acrobat · Bates number format and examples · Bates numbering a discovery response without a lawyer · Exhibit numbers vs Bates numbers · Redacting SSNs and account numbers in court filings · Redacting a bank statement · Why black box redactions fail · Redacting a PDF on iPhone or Mac · A document production index · Rolling productions · Responding to a request for production · Bates and redaction tools compared · batesstamp.com alternatives · RedactifyAI alternatives · Adobe Acrobat alternatives for Bates and redaction