PDF Unlock
Take the password and the printing, copying and editing limits off a PDF you are authorised to change.
Only for documents you are authorised to change
Drop a PDF here
Nothing is uploaded. The password is checked in this page.
The open password or the owner password. Leave blank if the file opens without a prompt.
What this file currently permits:
Only for documents you may change
The password is verified against the file before anything is decrypted. Nothing here guesses or brute-forces a password you do not have.
Everything here runs on your device. Nothing you enter is uploaded or stored.
Remove the open password and the printing, copying, editing and annotating limits from a PDF, leaving a file that opens with no prompt and behaves normally in every reader. The password is checked against the document before anything changes, and the file never leaves your browser.
How to use it
- Drop or choose the locked PDF. The panel names its cipher, key size and restrictions.
- Type the open password or the owner password — either works.
- If the file opens without a prompt but blocks printing, leave the box blank.
- Press Unlock. The unlocked PDF downloads immediately.
The two kinds of locked PDF
Files that prompt you for a password and files that open freely but refuse to print are locked in the same way and unlocked by the same operation, which surprises most people. Both carry the same encryption; the difference is only which password is blank.
A PDF stores two password hashes. One corresponds to the open password, without which a reader will not display a page. The other corresponds to the owner password, which grants full rights and makes the permission flags apply. A document with restrictions but no open prompt simply has an empty open password — which is why leaving the box blank unlocks it, and why “remove restrictions” and “remove password” are not two different tools.
What it does, precisely
The password you type is run through the specification’s authentication algorithm and compared against the hashes in the file. Only on a match is the encryption key derived. Every string and every stream in the document is then decrypted with its own per-object key, the security dictionary is deleted — object and all, so the hashes are not left sitting in the output for anyone to attack offline — and the file is written out.
Nothing is re-rendered and nothing is recompressed. Fonts, images, form fields, bookmarks and metadata come back as the exact bytes they were before encryption. The only visible difference is file size: objects are written individually rather than packed into compressed containers, which is a few percent larger and entirely cosmetic.
Where it stops
RC4 only. The standard security handler at revisions 2 and 3, which covers every PDF encrypted before roughly 2008 and a great many since, is fully implemented. AES, introduced with revision 5, is not — and the tool names it and declines rather than producing a file that looks unlocked and opens to garbage.
Some PDFs also keep their internal object table inside an encrypted compressed stream. Reading those requires decrypting them, and decrypting them requires reading them; there is no order that works without a full parser built around the cipher. Those files are reported as unreadable, untouched.
And there is no password recovery. A wrong password is reported as wrong. Nothing here guesses, dictionary-attacks or bypasses authentication, which is deliberate: this is a tool for opening your own locked documents, not for opening other people’s.
Which tool for which job
| You have | Use |
|---|---|
| A PDF that asks for a password you know | This tool |
| A PDF that opens but will not print | This tool, blank password |
| A PDF you want to lock instead | PDF Password Protector |
| A PDF whose password you do not know | Nothing here can help |
Questions
Do I need the password?
You need one of the two. The open password is what a reader prompts you for, and the owner password is the one that grants full rights over a document that already opens freely. Either will work here — the tool tries the open password first, then the owner password, and tells you which one succeeded. If the PDF opens with no prompt but refuses to print or copy, it has an owner password only and a blank entry will unlock it. What the tool will not do is proceed without authenticating — nothing is guessed and nothing is brute-forced.
Why does it refuse some files?
Two reasons, both stated when they happen. Files encrypted with AES — the default in Acrobat 9 and later, revisions 5 and 6 of the security handler — are outside what this tool implements, and it says so rather than producing a damaged file. Separately, some PDFs store their internal objects inside encrypted compressed containers, which cannot be read until the file is decrypted and cannot be decrypted until they are read, so those fail at the reading step. In both cases the original file is untouched.
Is the quality or content changed?
No. Unlocking is a decryption rather than a re-render, so every page, font, image and piece of metadata comes back to the exact bytes it had before the file was encrypted, and the tool verifies stream lengths rather than re-compressing anything. The one structural change is that objects are written out individually instead of packed into compressed containers, which makes the file slightly larger and has no effect on how it looks or prints.
Is this legal to use?
Removing protection from a document you own, made, or have been given permission to change is ordinary file maintenance — recovering your own archive, printing a statement your bank locked, editing a form you were sent. Removing it from someone else's copyrighted or confidential material is not, and in many places is specifically unlawful regardless of how easy it is. This tool authenticates before it decrypts precisely because that line matters. It is not a password cracker and will not become one.
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