How To (Properly) Redact a PDF

Redacting a PDF seems like it would be the easiest PDF editing task in the world. Just draw one of those black boxes over the text you need to have disappeared, and voila! Redacted! Except that your recipient can actually just place their cursor over that part of the document, copy, and paste it into a new document.

This is exactly what happened a few years ago in a patent infringement lawsuit involving Apple and Samsung. The judge’s decision contained redactions, but a simple copy and paste revealed everything beneath. If you want to make sure you’ve actually redacted something before sharing it, there are several methods—all of which are more secure than the black box.

Redacting Using Adobe Acrobat Pro DC

You probably already have Adobe’s Acrobat Reader, because everyone does, but you can’t perform redactions with it. You gotta have the Pro version to redact. Redacting in Adobe Acrobat Pro is very simple. The main problem with this method is you need Adobe Acrobat Pro. It is not cheap. 

You can buy a subscription the desktop software, Mac or Windows starting at $14.99 a month if you agree to a year-long commitment. Acrobat Pro is $24.99 if you want to go month-to-month. It offers a lot of features to edit, review, and create PDFs, so it’s worth the purchase if you’re a frequent user of PDFs. 

If redaction is a real rarity (as in a one-time thing), you can download a free 30-day trial of Adobe Acrobat Pro.

Adobe provides an overview of how to redact documents and remove sensitive information. It really only takes a few clicks.

First, open the document you wish to redact, go to the Tools menu, then select Redact.

Adobe tools redact

Doing so will bring up the redaction tools when you hop back to your document. Select Mark for Redaction and Adobe will pop up a handy reminder that redacting is a two-step process.1

Adobe mark for redaction

From there, just highlight the text you want to redact. Acrobat will outline it for you in bright red.

adobe redact highlight

Click Apply to redact… but first, Acrobat will ask if you are really sure you want the material gone.

Adobe are you sure you want to permanently remove content marked for redaction

Click OK and your text will disappear forever. Acrobat will then ask you if you want to find and remove any other hidden information.

Adobe redaction successfully applied

You should always say yes to this. Acrobat is asking if you want to remove the metadata, and you always want to remove the metadata. In this document, there’s nothing particularly secret, but the metadata does let you know I’m on a Mac and that I made this PDF with Microsoft Word originally.

adobe remove metadata

Scrubbing the metadata ensures that any author information, revision information, or anything similar gets completely excised from the document. There is no reason to ever hand over a PDF before you’ve scrubbed the metadata.

Paid Alternatives To Adobe Acrobat Pro

The cost for Acrobat Pro DC can add up over time. Unfortunately, super-cheap or free PDF redacting is hard to come by. Most of the free PDF redactors online require you to upload your document to the website before you can redact, which raises all sorts of ethical and security concerns.

There are a few alternatives, though. If you are on a Windows machine, consider NitroPDF, which will run you $159/user. You can get a free two-week trial to check it out. Foxit makes Foxit Redactor, which is software solely to redact Microsoft Word documents. It’s an Office plug-in, so you access the redaction tools within Office itself, which is handy. It costs you $39.95 and also comes with a free trial so you can see if you like it. However, Redactor only works on Windows and only works within Office, so it is limited to documents you create (or already have in an Office format), not PDFs you’ve received.

Another option for Windows users is PDF-XChange Editor, which will set you back $54.50. It offers a number of features, including a redactions. It does offer a free version with reduced features if you want to give it a try. 

For Mac (Windows, and Linux) users, LibreOffice is an office suite that allows you to edit PDFs. It’s free to use, however, it doesn’t have a function that redacts texts. Instead, you’ll have to “Find & Replace” what you want to redact with block symbols, which is a cumbersome process if you have a large document or many things to redact.

Make Sure Your Document is Redacted

For the more thorough or paranoid among you, after you’ve redacted a PDF, use another PDF editor to make sure someone else can’t just open up your document and unredact it. You should also open your document in a text editor and search for what you redacted to make sure it doesn’t show up that way either.

Old-School Redacting

Sometimes low-tech (or no tech at all) is the easiest-and cheapest-approach. Print out your PDF, black marker the heck out of it, scan it, and send it. Just remember you really do need to make a few passes with that black marker to completely obliterate things.

If you don’t feel like printing, marking, and scanning, you can do something similar via computer. Take your PDF and draw a black box in Acrobat Reader or Mac’s Preview or any similar PDF reader. After you do that, take a screenshot of your document. The resulting image is just that—an image—and therefore can’t be manipulated in Word or any other program. The problem with these two methods is that you are left with a document that isn’t searchable or conducive to redlining or commenting.

Bottom line: If you are in the type of practice that requires a good deal of document redacting, it is probably best to invest in a dedicated program that ensures the data you’ve redacted is actually gone. The price will be worth the peace of mind.

Updated March 26, 2019 by Aretha Soderstrom.

Check out our Legal Technology portal page to learn more about PDFs and other software to help your practice.


  1. Nonsense text for this document courtesy of Office Ipsum

25 Comments

  1. Avatar Duke Vukadinovic says:

    Hey Lisa,

    While redacting a PDF seems the easiest thing in the world, it’s not. I agree with your suggestion that if someone is in the type of business that requires a good deal of document redacting, he should definitely invest in a dedicated program.

    Really enjoyed reading this post!

  2. Avatar Brian Kurtyka says:

    Is it possible to uncover the so-called “black box” redactions if the pdf is password protected? All cut/copy/paste functions appear to be locked when I do that.

    • Avatar Sam Glover says:

      Well, it’s not redaction as required by the courts because the information is still in the document.

      Using a password will make it harder to get at that information, but I bet it’s still possible. It might not even be that difficult.

  3. Avatar Phacetious Plebbe says:

    Using the feature of the black box/bar in Preview on the Mac is certainly an option, but then you can make it better by exporting it as a PDF so that the “screenshot” is actually a conversion of the entire document, not just what is on the screen at the time.

    • Avatar Sam Glover says:

      That doesn’t work. The black boxes are still exported as a layer separate from the image. If you OCR the resulting PDF, you can still get the underlying text.

      • Avatar Phacetious Plebbe says:

        Sam, thanks for letting me know. Good thing I don’t practice civil or commercial law! I would probably be dead in the water. In any event I have a copy of Adobe Acrobat X Pro, so I can use that for the redaction.

  4. Avatar DJ says:

    You can redact for free using Foxit Reader. Just highlight the text OR draw a rectangle over the text (both options are in the Home menu). Right click on the text/rectangle, click properties, and set the two color boxes to black (two b/c the colors are for the border and the middle of the rectangle), and save those color selections as the default so you dont have to do that again.

    Now the blacked out part isnt technically redacted. If you save the file, the box/highlights can be removed. But if you print out a hard copy of the document, this method will obscure whatever text you put it over. Then you just need to re-scan the hard copy.

    • Avatar Sam Glover says:

      That is not redaction unless you print out the document with black rectangles and then re-scan the printed document. You’ll also want to carefully keep track of which version of the document is the redacted one and which one just has black rectangles.

      It’s basically the same thing as using a black marker, and just as clunky.

      The bottom line is that if you are regularly redacting documents, just get Adobe Acrobat Pro. It is the right tool for the job.

      • Avatar DJ says:

        You primary objection seems to be reiterating my last paragraph.

        I disagree that it is anything near as clunky as using a marker. This is a method I use several times a week on 1-2 pages. It is very fast and produces very professional looking results (unlike a marker). And best of all it is free and foolproof. You cant accidentally do it the wrong way and disclose confidential information.

        Acrobat is insanely overpriced. Even if you wanted an easier process than I described, that reductionist advice is unnecessary.

        • Avatar David K. Hiscock says:

          I’m with DJ on this one, Sam.

          My office rarely needs to redact document content, so Acrobat’s insane over-price is even _more_ of an obstacle.

          I highlight, change from yellow to black and “print” as a PDF, indicating “note marked changes”.

          I get a document that has blackouts where I want ’em.

          Physically printing and re-scanning or saving the file as an image, rahter than text may be yet more secure.

          • Avatar Sam Glover says:

            There’s no disagreement here. Your method and DJ’s absolutely works. The problem is that a lot of lawyers, courts, legislatures, etc.—including some in these comments—seem to think it works even if you don’t take the time to print out a hard copy of the document and then re-scan it.

            So I think it’s worth reiterating again and again that you cannot properly redact a document just by drawing black boxes. It only works if you print out a hard copy and then re-scan it.

  5. Avatar anith says:

    Most e-discovery review software has the ability to redact documents and then produce the document. This way you still have access to the original content for your own review and search, but the produced documents are redacted for everyone else.

  6. Avatar Diane says:

    Nice instructions! Thank you. Whatever program is used, it is often difficult to find good, clear instructions.

  7. Avatar Amie Colbert says:

    Valuable suggestions

  8. Avatar Bailey Coppage1 says:

    I love it! Excellent article. I had a good experience filling forms online and happy to share it with you. Just look at the service https://goo.gl/WGhsgl Its pretty easy to use. I think you can get a free trial if you ask for it.

  9. Avatar James says:

    Here’s my method. I believe it works in regular Acrobat, and older versions of Acrobat Pro that don’t have the redaction tool.
    1. Get yourself a .jpg that you will use as a redaction box. It can be a picture of a black rectangle, or whatever. (I know what you’re thinking, but keep reading)
    2. “Add Image” the .jpg into the document you want to redact. Adjust the size and position to cover up the text you want redacted.
    3. Use the “Remove Hidden Information” option. In Acrobat Pro IX, it’s under Tools–Protection–Remove Hidden Information. Among other things, it will detect “Hidden text”–whatever is under the redaction box. Make sure that checkbox is ticked, then click “Remove.”
    4. The text underneath the box is now erased. You can double check this by using the “Edit Text & Images” option to move the box and see for yourself. (Note that if it’s a document with editable or OCR text in the first place, you can just skip the box and just erase the text directly.)
    It’s a clunky method, but works for the occasional redaction without having to purchase new software beyond regular Acrobat.

  10. Avatar Tiffany Patterson says:

    Thanks for this. I have this program but didn’t realize I could redact in it. We’ve been using the old school method. This article may change my life. Thanks.

  11. Avatar Jim Calloway says:

    Nice article, but the omission of Power PDF Advanced 2 is puzzling. At $149 per license, it is a worthy Adobe Acrobat substitute that handles redaction well.

  12. Avatar Fara Daun says:

    I would like to add that the redaction tool in Acrobat Pro is fantastic and it is only one of several extremely valuable e-discovery tools in that program. It also has super easy Bates numbering and will consecutively number large sets of .pdf documents at once, then you can simply change the starting number and do another set. This makes keeping logs easy. It will also search an entire drive or directory of documents for a particular term or phrase within the documents, which is helpful when opposing counsel sends documents titled solely by their Bates number, and on which you can’t do from a normal directory search. It will also OCR multiple documents at the same time and doing so is often faster than doing them one document at a time. I am still on version 9 so I assume the new versions have even better tools, but these have saved me hours. As a result, the $450 or so for a desktop copy is a good bargain. The cost is equivalent to a couple of billed hours (or less) but the search feature saved me many times that the first time I had to found the “smoking gun” document that I knew had to exist but that was buried in gigabytes of data. There is no way my small client could have paid for that kind of manual search and there is no way I had the time to do it.

    However, when scrubbing metadata, be aware that some parties (and some government agencies) completely freak out and get quite threatening when faced with a document or set of documents lacking metadata. I’m not saying to include it, I’m just saying that, faced with such a party you will have to argue about it and if they are bigger and have unlimited budgets it can be a powerful tactic.

  13. Avatar Eric says:

    I realize this is an older topic, but I have a question. I’m dealing with a government agency that sent me a so-called “redacted” document that didn’t have the usual black boxes on it. If I am to believe them, they redacted in white, so that the fields simply look like they were left blank. So how do I know if they actually redacted it or if the fields weren’t blank the whole time?

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