How to Redact a PDF on Mac, Windows, or Chromebook

By the SladdPDF team · Published August 23, 2026 · Updated August 23, 2026

Only one of the three big desktop platforms ships a real PDF redaction tool: to redact a PDF on Mac you can use Preview's built-in Redact tool, which removes the text it covers. Windows and ChromeOS have nothing equivalent — Microsoft Edge and the Chromebook Gallery app can only draw on top of a page, which leaves the text underneath fully intact. This guide covers what each platform actually does, where each one fails, and the one method that works identically on all three.

How do I redact a PDF on Mac?

Use Preview's Redact tool: open the PDF, choose Tools → Redact from the menu bar (or click the Markup button, then the Redact button), confirm the warning, and drag across the text you want gone. This is a real redaction feature, not an annotation — Preview tells you outright that redacted content is permanently removed, and it becomes permanent when you save.

Preview is also the reason Mac users are so often caught out, because for years the standard advice on the internet was wrong. Before macOS Big Sur, Preview had no redaction tool, so people drew a black rectangle with the Shapes tool and saved the file. That rectangle is an annotation sitting on a layer above the page; the words underneath stay in the PDF, ready to be selected, copied and searched. Apple now warns you if you try it: pick Shapes over sensitive text and Preview says the content behind the annotation will not be deleted, and points you at the Redact tool instead.

Step by step in Preview

1. Duplicate the file first (File → Duplicate). Redaction is meant to be irreversible, and once you save you cannot get the original text back.
2. Open the copy in Preview.
3. Choose Tools → Redact, or click Markup and then the Redact button on the left of the toolbar.
4. Click OK on the warning about permanent removal.
5. Drag the cursor across each piece of text or image you want removed. Drag over an existing redaction again to undo it while you work.
6. Save with Cmd+S, then quit Preview.
7. Reopen the saved file in a different app and try to select and search the redacted words.

Where Preview still falls short

Preview handles the text it can see, and not much else. When Howard Oakley of The Eclectic Light Company tested the tool against a PDF crafted with invisible text running off the edge of the page, Preview removed the visible text but left readable fragments of letters — and the hidden off-page text was untouched, and was recovered afterwards with Acrobat's Sanitize tool. His conclusion is worth repeating: PDF was never designed for redaction, and a document can hold thousands of objects, including leftovers from earlier edits that carry invisible text.

Two more caveats before you send anything. First, Preview has no sanitize step: it works on page content and does not strip document metadata such as author, title and creation tool, which is exactly the kind of leak covered in our guide to removing metadata from a PDF. Second, Apple's own support forums carry recurring threads from users who could still find redacted words with Cmd+F after saving in the same session; several report the text is genuinely gone once the file is closed and reopened. Either way, the lesson is the same — quit, reopen in another app, and check.

How do I redact a PDF on Windows?

Windows has no built-in way to truly redact a PDF, so you need a third-party tool. The default PDF viewer on Windows 10 and 11 is Microsoft Edge, and Microsoft's own documentation for its PDF reader lists highlights, inking with a pen and text notes. Those are annotation features. Every one of them draws on top of the page and leaves the text layer completely intact — the same failure mode as the old Preview rectangle trick, explained in detail in why a black box is not redaction.

Adobe's redaction tool is real, but it lives in Acrobat Pro. The free Acrobat Reader can view, comment on and fill PDFs; redaction is a paid feature. If you redact documents daily and need batch processing and audit trails, a paid desktop licence is the honest recommendation. For occasional use it is an expensive way to black out three lines.

The one Windows tool that does redact — with a catch

Windows 11's Snipping Tool genuinely redacts, but it works on screenshots rather than PDFs. Capture an image, hit the Text actions button to run OCR over it, and you can either select text and redact it manually or use Quick Redact to black out every detected email address and phone number in one click. Because the output is a flat image, the covered characters are not in the file at all.

That makes it a workable last resort for a one-page PDF: display the page full-screen, capture it, redact, and save a new image. The catches are real, though. You get one image per page, unsearchable and at screen resolution; the tool only redacts text its OCR can read, so handwriting, logos and faces are your own responsibility; and you must save a fresh copy, since the black bars are still undoable until the file is written out.

The other workaround you will see recommended is a Word round trip: open the PDF in Microsoft Word, delete the sensitive text, then export a new PDF. It does delete the text, but Word rebuilds the layout from scratch, so tables, headers and line breaks move — and on a signed or scanned document, the result is often unusable. Check every page if you go that route.

How do I redact a PDF on a Chromebook?

On a Chromebook you redact a PDF in the browser, because ChromeOS has no built-in redaction anywhere. The Gallery app is the system PDF editor, and Google describes what it can do plainly: fill out PDF forms, add text annotations, add highlights, and sign documents with free-hand annotations. Useful features — but all of them add content rather than remove it.

Google says so itself. Its Chromebook help page on redacting and deleting PDFs states that you can use the Draw function in Gallery, or Google's PDF reader, to cover text or images, but that this does not redact the document and the underlying images or text can still be accessed. It recommends a dedicated redaction tool instead.

There is a second, less obvious Chromebook trap in the same help page: deleting pages in the Gallery PDF editor leaves the corresponding bookmarks intact. If a bookmark title contains a name or a case number, removing the page does not remove that information from the file.

You can install Android or Linux apps on most Chromebooks, but then you are back to installing software and verifying whether its "redact" button deletes anything — the same question we work through in our guide to redacting a PDF on iPhone or Android. For a Chromebook, a page you simply open in Chrome is a better fit, and it needs no permissions at all.

Which platform gives you true redaction?

Only macOS ships true PDF redaction out of the box, and even there you should verify the result. Here is the honest summary:

If your method is not in a "Yes" row, treat the file as decorated, not redacted.

The cross-platform answer: one tool, three platforms

The simplest way to redact a PDF on Mac, Windows and Chromebook without learning three different apps is to do it in the browser. A page is a page: the same tool loads in Safari on a MacBook, Edge on a work laptop and Chrome on a Chromebook, and behaves identically on all three. Nothing to install, no admin rights, no app store, no account.

That is what SladdPDF, a free browser-based PDF redaction tool is built for. The important part is where the work happens: your PDF is opened and processed locally in your own browser using JavaScript and WebAssembly, and it is never uploaded to any server. Once the page has loaded you can go offline and it still works — a useful sanity check, and the reason we think handing a sensitive document to a random converter site is the wrong instinct. That argument is laid out in why no-upload PDF tools are safer.

The workflow, identical on macOS, Windows and ChromeOS:

1. Open sladdpdf.com in Chrome, Edge, Safari or Firefox. There is nothing to install and no account to create.
2. Drag your PDF onto the page. The file is opened and processed locally in the browser and is never uploaded to a server.
3. Draw a box over every name, number and detail you need to remove. Use the page thumbnails to check each page and Ctrl+Z to undo a mistake.
4. Choose Secure mode, which rasterizes each page to a flat image so the text layer and hidden objects are destroyed, and switch on metadata removal.
5. Reopen the exported file in a different viewer and try to select, copy and search for the redacted words. Nothing should be found.

Three honest caveats. The free version exports at standard resolution; high-resolution 300 DPI export requires a Pro licence key — the page count is unlimited. There is also a Fast mode that draws vector overlays instead of rasterizing — it is quicker and keeps the file smaller, but the tool warns that underlying text may in some cases still be extractable, so Secure mode is the right choice for anything sensitive. And if you redact hundreds of documents a month, need OCR on scans, or need an audit trail for court or compliance work, a paid desktop application such as Acrobat Pro is a better fit than any free tool, ours included. For everything else, the step-by-step basics are in our complete guide to redacting a PDF for free.

How do I check that the redaction worked?

Verify every redacted file before you send it, whichever platform you used — the check takes thirty seconds and it is the only thing that actually proves the text is gone. US federal court guidance on PDF redaction makes the point bluntly: a black box drawn over data merely hides it, and anyone can copy the covered area and paste the text somewhere else to read it. Filers, not clerks, carry the consequences.

Run these four checks on the exported file, in a different application from the one you redacted in:

• Select and copy. Drag across the blacked-out area and paste into a text editor. Anything that appears was never removed.
• Search. Press Cmd+F or Ctrl+F and search for a word you redacted. Zero hits is the only acceptable answer.
• Select the whole page with Cmd+A or Ctrl+A, copy, and paste. This catches text hidden outside the visible area — the exact failure that defeated Preview in testing.
• Check the document properties for author, title and creation tool. Redaction and metadata are two separate jobs, and files leak names through both.

Close and reopen the file before you test. Some viewers, Preview included, keep a search index from the editing session that can make already-deleted text appear to still be there — and a cached hit is not the same as a real one. If the file passes all four checks after a clean reopen, you are done.