Your options at a glance
Real redaction, local, free. Apple documents two caveats (see below).
Not redaction. The text is still in the file under the ink.
The most complete option. Free PDF readers generally do not redact.
File never uploaded. Needs a connection to open the app and sign in.
Preview details from Apple's Preview User Guide, consulted September 30, 2026. For desktop, online and browser tools side by side, see the PDF redaction tool comparison.
On a Mac: what Preview can and cannot do
Preview, the PDF viewer that comes with macOS, has a genuine redaction tool. Apple's Preview User Guide describes the Redaction Selection tool as a way to “select text to remove it from view”, and adds that “once you close the document, the redaction becomes permanent.” For a short text PDF where you know exactly what to remove, that is enough, and it costs nothing.
Its limits are worth knowing before you rely on it:
- It is manual. Preview does not look for account numbers or e-mail addresses for you; every occurrence has to be found and selected by eye.
- Apple notes that “if the PDF has a table of contents, entries in it that link to redacted text aren't removed.” A heading you redacted on page 12 can still be listed in the sidebar.
- Preview works on the file you opened. Duplicate the PDF first if you need to keep an unredacted original.
On the Mac, RedactOffline runs in Safari, Chrome, Firefox or Edge. The exported file lands in your Downloads folder as name_redacted.pdf; your original is never modified. Open the result in Preview and use Cmd+F to search for a value you redacted: it must not be found.
On Windows: why a black highlighter is not redaction
On most Windows PCs, PDFs open in Microsoft Edge. Edge lets you draw and highlight on a PDF, and it is tempting to pick black ink and scribble over a name. The page looks redacted. It is not: the ink is an annotation laid on top of the page, and the text underneath is untouched. Anyone can select it, copy it, or delete the annotation.
The same goes for a black rectangle in Word before “Save as PDF”, or a black shape in any PDF editor that is not a redaction tool. The guide to blacking out text shows how to test for it.
The standard fix on Windows is to install a desktop PDF editor with a real redaction tool — checking that the edition you buy includes redaction, since some suites reserve it for their higher tier. If you cannot or do not want to install software, open RedactOffline in Edge, Chrome or Firefox instead. After export, open the file from your Downloads folder, press Ctrl+F and search for a value you redacted; nothing should be found.
The browser route: the same steps on every computer
Because the editor runs inside the browser, the steps are identical on a Mac, a Windows PC, Linux or a Chromebook.
- Go to redactoffline.com and sign in with a free account.
- Drop your PDF on the editor. It is read from your disk into the browser tab — not uploaded.
- Review the boxes placed on detected data: e-mail addresses, phone numbers, IBANs, card numbers, ID and passport numbers, dates, postal addresses.
- Add names and other known terms to the custom terms list, and draw boxes over anything else.
- Export. In the export dialog, open “Document metadata” and clear the author and title if they identify anyone.
What “offline” means here
Your document is processed on your own computer — reading, text recognition, detection and export all happen in the browser tab, and the file is never sent to a server. It does not mean the website works with no internet at all: you need a connection to open the app and sign in. The security page explains the architecture.
When a desktop application is the better choice
- You redact long documents every day. The free plan covers documents up to 5 pages, and export redraws every page, which takes noticeably longer than a desktop save.
- You need the output to keep its original vector text, links and form fields. The browser export turns pages into images with an invisible text layer.
- You need labelled redactions — exemption codes or overlay text inside the boxes. RedactOffline's boxes are plain black.
- Your documents are in a language other than English or French and are scanned: the built-in OCR only loads those two languages.
Frequently asked questions
Can I redact a PDF on a Mac for free?
Yes. Preview, which ships with macOS, has a Redaction Selection tool for text you select by hand. RedactOffline's free plan also works on a Mac, in Safari, Chrome, Firefox or Edge, and adds automatic detection and OCR for documents up to 5 pages.
How do I redact a PDF on Windows without installing software?
Open redactoffline.com in Edge, Chrome or Firefox and use the editor there. Nothing is installed, and the file is processed inside the browser rather than uploaded. Do not use a black highlighter or a drawing tool: that covers the text but leaves it in the file.
Does it work on a work computer where I cannot install software?
Usually, yes: it only needs a recent browser. Some organisations restrict which websites can be opened, or block file access from the browser, so check with your IT team if the editor does not load.
Does 'offline' mean I can use it without internet?
It means the document is processed on your computer, not on a server. You need a connection to open the app and sign in; the file itself is never sent anywhere.
Does it work on Linux or a Chromebook?
The editor runs in any recent Chrome, Edge, Firefox or Safari, so the operating system underneath does not matter. Most desktop PDF suites are published for Windows and macOS only.
Redact in the browser you already have
Mac, Windows, Linux · Nothing to install · Free plan for documents up to 5 pages
Open the editor