Inspect PDF encryption level, password restrictions, printing rights, copying permissions, and digital signature status online free.
100% Free & Private â Processed entirely inside your web browser without server uploads
đ Open đ PDF Security SuiteSending a sensitive document over email or chat without password protection is like mailing a postcard with your bank account details printed on the back. Anyone with access to an inbox or network router can read it. On the flip side, having to enter a 20-character password every single time you open your own bank statement or monthly payslip gets old very fast.
Most online "PDF unlockers" and "password protectors" require you to upload your confidential document directly to their cloud servers. If that file contains your tax identification, home address, medical history, or trade secrets, sending it to an unknown third-party server creates an unnecessary privacy risk.
I built this all-in-one PDF Lock & Unlock tool on SmallPDF Pro to solve both problems cleanly. Everything runs 100% locally on your computer or mobile device using modern client-side cryptographic engines. Your documents never touch our servers or any cloud database. When you lock a file, standard 128-bit encryption is applied right in your browser memory; when you unlock a file, the password is authenticated locally and an unencrypted copy is produced for immediate download.
Select the "đ Lock PDF" tab if you want to add a password to an unprotected file, or "đ Unlock PDF" if you want to remove the password from an already protected document.
Drag your document into the upload zone or click "Browse Files". The document loads into your browser memory instantly without uploading to the internet.
When locking, enter a strong password (and an optional owner password) and choose whether you want to prevent unauthorized printing or text copying. When unlocking, simply type the current password to authenticate.
Click "Lock PDF" or "Unlock PDF". The browser computes the cryptographic changes in a fraction of a second, and your new document is ready for instant download.
Never. SmallPDF Pro is architected with a strict privacy-first model. The cryptographic calculations happen purely inside your browser. We never see your files, your passwords, or your document contents.
A User (or Open) Password is required for anyone to open and read the PDF. An Owner (or Permissions) Password lets you set restrictions, such as preventing other people from printing the file or copying its text, while still letting them view it.
No ethical software can instantly bypass strong PDF encryption without the password. If a document is locked with an open password, you must know and enter the valid password to unlock it. Once authenticated, our tool strips out the security layer so you never have to type the password again.
Yes. Our engine generates standard, spec-compliant PDF security dictionaries. Any standard PDF reader (Adobe Acrobat, Preview, Chrome, Edge, Android, iOS) will prompt for the password normally.
Because processing happens directly on your device, there are no artificial cloud upload limits. Most files up to 100MB or several hundred pages process smoothly within seconds.