Merge, shrink or upload a locked PDF: unlock it first

The short answer: unlock, then everything else

A PDF that needs a password to open can't be merged, shrunk or read by most upload portals, because those tools have to see what is inside the file. So take the password off a copy first, with Unlock PDF, which needs the password you were given. Then use the unlocked copy for the rest:

1. Unlock every locked file, in one go.
2. Merge the copies into one file with Merge PDF, if you need one file.
3. Shrink it to the size limit with Resize PDF or the compressor.
4. Upload it, or lock it again with your own password with Protect PDF before you send it by email.

All of these run inside your browser, so your statements and passwords are never uploaded. The rest of this post follows the routine step by step, with what each tool says when it meets a locked file.

Why other tools refuse a locked file

A PDF locked with a password has all its parts scrambled with a key that only the password unlocks. A tool that merges, shrinks or checks the file has to read those parts. Without the password, it can't. So each of them says no, in its own words:

• Merge PDF shows on the file's card: "Locked with a password. Unlock it first, then add it again."
• Resize PDF and the compressor can't work on a PDF that needs a password to open, as it is. They tell you to remove the password first with Unlock PDF, which needs the password.
• Upload portals, for a loan, a visa, a rental agreement or a job, often can't read such a file, and turn it away or show an error such as "file corrupt" or "unreadable".

That is the same reason you can't print from another app or merge the monthly statements: the lock is doing its job. It is a good way to send a file, and a nuisance afterwards. An unlocked copy fixes that, and your locked original stays as it was.

Step 1: unlock all your files at once

Open Unlock PDF and add every locked file: press Choose locked PDF and pick them, or drop them on the page. Each file gets a row, and its lock is checked straight away.

• Type the password once. Statements from the same bank usually share one password. Type it on any row and press Unlock: the page tries it on every file still waiting for a password. Twelve monthly statements need it typed only once. A file with a different password keeps its box, ready for its own.
• Check the row. It says what the file was locked with, such as AES 256-bit, and what was blocked, like printing or copying.
• Download each copy, or press Download all, which saves them in one ZIP file, unlocked-pdfs.zip. Each copy's name ends in -unlocked, like statement-march-unlocked.pdf.

It is quick. In our tests, a sample one-page salary slip took 0.1 seconds, a 14-page paper 0.2 seconds, a 117-page textbook 0.4 seconds and a 42-page, 47.8 MB scan 1.3 seconds. A 400-page scan of 454.8 MB took 11.3 seconds. A wrong password is said to be wrong in under 0.1 second for a small file. A phone may be slower than our test computer.

If you can't remember the password, Remove password from a bank statement PDF shows where to look. The tool never guesses a password.

Step 2: merge the unlocked copies

Open Merge PDF and add the unlocked copies. If you downloaded a ZIP, open it on your phone or computer first and pick the PDFs from inside. Then:

1. Drag the cards into the order you need, such as month by month. On a phone, drag by the numbered handle in the card's corner.
2. Leave the bookmarks on One per file, the default. A reader then gets a clickable list with one entry per month.
3. Press Merge and Download. The new file is named after your first file, like statement-march-unlocked-merged.pdf.

Merge PDF copies every page exactly as it is, so nothing gets blurry. The merged file is about as big as the files together. In our tests, three scans of 14 pages in all, 23.1 MB together, merged into a 23.1 MB file in 0.3 seconds.

One more way to get an unlocked copy, on a computer: in Chrome you can open the file, type the password, then print and save as PDF. That works for a single file; Unlock PDF is quicker for many.

Step 3: bring it under the size limit

Portals that want statements or salary slips often have a size limit. Bank and salary PDFs are usually typed, made on a computer, and that is a different case from scans:

• Check the size first. Typed PDFs are often small already. A typed one-page form was 33 KB in our tests, and an unlocked copy is often a little smaller than the locked one: our 14-page paper went from 994 KB to 926 KB.
• Typed text has a smallest size. Text and fonts are copied exactly as they are, so they can't shrink much. A long statement may not fit a small limit. Our 14-page typed paper could not go below 766 KB.
• Send only the pages the portal needs, using Split PDF, such as the last three months instead of the whole year.
• If the limit is exact, use Resize PDF and type the size. For a typed file that says Over, read Typed PDF over 200 KB? Why it won't shrink and how to fix.

Always shrink last. The limit is checked on the file you upload, so shrinking each statement first and then joining them adds up the sizes again.

Step 4: upload it, or lock it again before you send it

You now have a file the portal can read. Two cases:

• Uploading to a portal. Upload the unlocked copy. The portal's own security protects it there. Rename it if the portal asks for a certain name.
• Sending by email or chat. Don't send the unlocked copy. Lock it with a password of your own using Protect PDF, and tell the password another way, such as in a phone call. The post Send bank statements and ID scans safely: lock the PDF first has the routine.

Then tidy up. An unlocked statement in your Downloads folder can be opened by anyone using your phone or computer. Delete the copies you no longer need after uploading, or keep them in a folder only you can open. Keep the locked original for your records, as it is still protected.

If the PDF opens, but other tools still say no

A PDF can carry two kinds of lock, and only one of them is a password to open:

• Editing restrictions. A file that opens without a password but doesn't allow changes can be merged, and the merged PDF opens without those restrictions. The result tells you so. For printing and copying limits, Unlock PDF removes them with no password needed. See PDF password vs restrictions.
• A digital signature. A signed PDF, such as an e-signed agreement, can be merged, but the merged copy no longer carries a valid signature, since the signature covers only the file as it was signed. The result says so. If someone must check the signature, send the original too.

Unlock PDF opens locks made with a password, the standard PDF way: RC4 40-bit and 128-bit, AES 128-bit and AES 256-bit. A lock opened by a certificate or an app instead of a password can't be opened, because there is no password to type.

Use it on your own papers

Unlock PDF is meant for documents that are yours or that you are allowed to use: your statements, your salary slips, your certificates, and files a colleague or a client sent you to work with. Removing a password you were given is much like opening the file and saving a copy. Restrictions on printing or copying sometimes protect someone's work, such as a book or a paid report. Respect the wishes of whoever made the file, and its copyright. When in doubt, ask the sender.

Your statements and passwords stay on your device

Locked PDFs are locked because they are private, so a tool that uploads them to unlock them defeats the point. None of these tools has an upload step, and none sends your files or passwords anywhere. The password is handed to a background worker on your device and forgotten when the page closes. The page contacts only this site and Google's ad service, which shows the ads that keep the tools free, and our code never gives your files to the ad code. The privacy policy has the details.