Stop others copying, printing or editing a PDF and what really works

The short answer: you can ask, but you can't force

Yes, you can switch off printing, copying and changes in a PDF. The honest part comes straight after: these blocks are a request that PDF apps are meant to follow. Many apps do, and some don't. The blocks stop casual copying by honest people, which is sometimes exactly what you want. They do not stop someone who is determined.

Here is how to set them with Protect PDF, in your browser:

1. Add the PDF with Choose PDF files.
2. Type a password to open the PDF, twice. The page always asks for one. It can't make a file that opens freely and only blocks printing.
3. Tick "Also block printing, copying or changes" and choose what to block: Printing, Copying text, Changes. All three are ticked to begin with.
4. Type an owner password, different from the first. It lifts the blocks, so keep it to yourself.
5. Press Protect PDF and download the copy. Its name ends in -protected. Your original is not changed.

People who know only the first password can open and read the file, but they get the blocks. You, with the owner password, can lift them.

How the blocks work: a sign on the door

A protected PDF holds two separate things. The first is the lock. The file's contents are scrambled with AES 256-bit encryption, and the password to open unscrambles them. That lock is strong.

The second is a short list of permissions: may this file be printed, may its text be copied, may it be changed? The list is a note attached to the file. It doesn't scramble anything more.

Think of the lock as a locked door, and of the permission list as a sign on the wall that says "Please do not photocopy". Once someone is through the door, the sign works only if they choose to obey it. A PDF app that respects the sign greys out the Print button, or won't let you select text. An app that doesn't respect it simply does the job.

Why can't the sign be stronger? Because to show a page on the screen, the app has to unscramble it, using the password to open. Once that is done, the whole file is readable, and the app could print or copy any of it. The only thing between that reader and a printout is the app's good manners.

The owner password is the key that tells a polite app "this person may ignore the sign". That is what "lifts the blocks" means, and it opens the file too. The password to open is a different thing. It is the real lock, and it is the one that keeps strangers out.

What each block does, and which to pick

Pick only what you need, because each block gets in the way of honest readers too.

• Changes only suits a quotation, an agreement or a notice, where you want the figures to stay as you sent them. Readers can still print and copy what they need.
• Changes and copying suits study notes or a report that you would rather not see pasted into other documents.
• All three is the strictest setting. Think first about whether your reader may need a printout, for a visa, a bank or a college.
• Blocking copying but not printing is a weak pair. Most phones and computers can "print" to a new PDF file instead of to paper, so a reader who may print can usually make a fresh copy that has none of your blocks. If you block copying, think about blocking printing as well.

The owner password must be different from the password to open, and the page won't let you use the same one. Make it long, keep it to yourself, and write it down somewhere safe. Keep your original file too, which Protect PDF never changes. It is your real master copy.

What we saw when we tested the blocks

We protected PDFs with the blocks on, and checked them in three PDF programs: Poppler (which many Linux apps use), pypdf (a PDF library for programmers) and qpdf (a PDF checking tool). All three showed printing, copying and changes as not allowed, and the owner password opened the file in each. So the blocks are written into the file correctly.

What that doesn't tell us is how every app on your readers' phones and computers treats the note. Safari, Preview on a Mac, Adobe's apps and the PDF apps on phones were not part of our tests. Adobe Acrobat Reader is one that follows such blocks, and many other apps do too, but each app decides for itself.

So test with the apps that matter to you:

1. Open the protected copy in the app your readers will use, and type the password to open.
2. Look at Print. Is it greyed out? Try to select some text and copy it. Try to edit or comment.
3. Try the owner password at the password box. In apps that ask for it, the blocks should lift.

If an app ignores a block, you now know that a reader using that app can ignore it too.

Where the blocks stop working

• Apps that ignore them. Many different people write PDF apps, converters and editors, and some of them never check the note.
• Tools made to remove them. They are easy to find, and one is on this site: Unlock PDF. Anyone who has the password to open your file can add it there and get a copy with nothing blocked. It accepts either password, so the owner password isn't even needed. Its page says it is for your own files and files you are allowed to use, and asks people to respect whoever made a file, and its copyright. But the fact stays: if one website can remove the blocks, others can.
• Other rebuilding tools. The guides of Merge PDF, Split PDF, Organize PDF, Rotate PDF, Add Watermark, Add Page Numbers and our compressor say that a PDF which opens without a password but blocks changes is accepted, and the new PDF opens without those restrictions. Files made by Protect PDF always need a password to open, so those tools turn them away until the password is removed.
• Screenshots and photos. A page on a screen can be captured or photographed. Blocks cannot stop that.
• Retyping, and reading text from pictures. A short passage can be typed again by hand, and programs exist that read the words in a picture.
• Printing to a new PDF. If printing is allowed, a reader can usually print the pages into a fresh PDF, which carries none of your blocks.
• People you trust. Whoever can open the file can pass it on with the password. Blocks don't change that.
• Nothing is hidden. Blocking copying doesn't hide your words. Anyone with the password to open can read every one of them on the screen.

Blocks don't decide who owns the work, either: removing them doesn't change who owns it. A clear line in your email, such as "please don't share this", tells people your wishes more plainly than a block does.

What really works, goal by goal

No single setting stops everything. What to use depends on what you fear:

The pictures route, step by step

A PDF whose pages are pictures has no text to select, so copy and paste does nothing. You can make one with two of our tools, on a phone or a computer:

1. Turn the pages into pictures with PDF to JPG, from the unlocked original. Normal sharpness suits most pages, and High suits small print. Several pages come as one ZIP file, so take the pictures out of it first (the file app on most phones and computers can open a ZIP).
2. Put the pictures into one PDF with JPG to PDF. Check that the cards are in page order before you convert. The JPGs go in exactly as they are, so nothing is blurred again.
3. Lock the result with Protect PDF if you wish.

Be clear about the cost. Search stops working. Screen readers can't read the pages aloud, which shuts out blind readers. The file is usually bigger than the typed original. Text in a picture also turns blurry if you zoom in far, where real text stays sharp. It stops copy and paste only, not a screenshot or a program that reads text from pictures.

Four examples, and what to do in each

These are examples, not real cases.

You email a price quotation to a customer

You want the figures to stay as sent. Block Changes only, and leave printing and copying on, so the customer can use it. Send the password to open by phone. Keep your spreadsheet or Word file as the master. The block doesn't stop someone retyping your figures into a new document, so if a changed copy comes back, Compare PDF can show what differs.

You share study notes with a class group

Tell the group the password to open in class, and block Copying and Changes. Be honest with yourself: one student can send the file and the password to someone else. First put the course name on every page with a watermark. That doesn't stop sharing, but a shared page carries the name with it.

A bank asks for a copy of your Aadhaar or PAN card

The bank must open, read and perhaps print it, so blocks help very little. A watermark helps more. Write the purpose and the date across the copy, such as "For bank account opening only", then lock the marked copy with a password and tell the bank the password by phone. Add the watermark first, because Add Watermark can't use a locked file.

You send a CV, or a form to be filled in

Don't lock a CV that a portal has to read. Some portals and offices can't accept password-protected PDFs at all. For a form you want filled in and sent back, Changes can be blocked while filling in the form's fields stays allowed. The people you send it to still need the password to open it.

Getting the most out of blocks

• Block only what you need. Every extra block is one more thing an honest reader can't do.
• Use a long owner password, different from the one to open, and never share it. Choose it the way you would choose any password that is hard to guess.
• Keep the unprotected original in a private place. It is what you will need when the file has to change.
• Tell your readers. A greyed-out Print button looks like a fault. One line in your email helps: "Printing is turned off in this PDF. Ask me if you need a printed copy."
• Send the password to open another way, not in the same message as the file, as the guide to adding a password explains.
• Give the file a plain name, because a locked PDF still shows its file name and size.
• Do all your other edits first. Merge, split, resize and watermark tools can't use a file that needs a password to open, so lock it last.

One more thing changes when you protect a file: a digital signature stops being valid on the protected copy. If a signature matters, keep the signed original too.

Questions people ask

Can I block printing but allow copying?

Yes. Tick only the blocks you want. Each one works on its own.

Can I make a PDF that opens with no password but can't be printed?

Not with Protect PDF, which always asks for a password to open. Other software can make such files, but the limits in this article apply to them too. If you can give your readers a password, a shared password to open with the blocks on does a similar job here.

Will it stop screenshots?

No. Nothing in a PDF can stop a screenshot or a photo of the screen.

Will blocking copying stop screen readers?

No. Screen readers that read the text aloud for blind people are still allowed, as the PDF standard asks.

Will it stop someone converting my PDF to Word?

Converters differ, and some ignore the blocks, so don't rely on them for this.

I can't print my own protected PDF. What now?

Type the owner password, not the password to open, when the app asks. In apps that accept it, it lifts the blocks. Or simply print the unprotected original that you kept.

I lost the owner password. Can I get the blocks off?

If you still know the password to open, Unlock PDF makes a copy with nothing blocked. Then you can protect the copy again. Only do this with files that are yours, or that you are allowed to use.

Do the blocks change how the PDF looks?

No. Nothing on the pages is redrawn. Once the password is typed, text, pictures, links, bookmarks and form fields are all as they were.