May 9, 2026 · Unlock PDF
How To Unlock A Password-Protected PDF You Own
Password-protected PDFs are great for sharing - and a hassle for the recipient who has to enter the password every time they open the file. If you're the owner and you have the password, removing the protection is a one-step operation.
Unlock PDF does this with qpdf - the same open-source tool used by professional prepress shops - on a short-lived Lambda worker.
We Don't Crack Passwords
Unlock PDF requires the original password. The tool decrypts a file when you supply the password used to encrypt it. We do not crack passwords, attempt brute-force attacks, or pretend to recover passwords from PDFs.
If you don't have the password, the file's original author does, and the right way to recover access is to ask them. Cracking encrypted documents you don't own is also illegal in most jurisdictions.
How It Works
You upload the locked PDF to Unlock PDF and enter the password. The file is sent over HTTPS to an isolated Lambda function that runs qpdf to decrypt it. The unlocked file is returned via a signed download URL that expires quickly.
The password is used once by the worker and never written to logs or storage. The unlocked PDF is deleted within 24 hours.
Why Server-Side
Most pdf9x tools run in your browser. Unlock is one of the exceptions because PDF encryption variants are messy - there are at least four common encryption modes plus a long tail of legacy schemes. qpdf handles them all. A JavaScript-only decryption tool would handle a fraction.
The tradeoff is upload. To keep this manageable, the worker is short-lived, the password is never persisted, and the file is auto-deleted.
After Unlocking
Once decrypted, the PDF works in every other tool on pdf9x - Merge PDF, Split PDF, Watermark PDF, all of them. To re-protect with a new password, use Protect PDF.
Have the password? Unlock PDF strips it in seconds. Files are deleted within 24 hours and passwords are never stored.