PDF · Security

Protect PDF.

Lock a PDF with a password so only someone who knows it can open it. AES encryption, computed entirely in your browser — the file never leaves your device. Free: 1 file. Premium: batch-protect unlimited files at once.

Inputs

Result

Choose a PDF, set a password, and press Protect PDF.

How it works

On-device: the encryption happens in your browser using the Web Crypto API. Your PDF and password are never sent to a server.
Standard AES encryption: the same protection level that Adobe Acrobat and other desktop PDF tools use, readable by any PDF viewer that asks for the password.
Not a cracking tool: this page only ever adds a password you choose. It has no way to guess, recover, or remove a password you don't already know — see Remove PDF Password for unlocking a file with a password you already have.

Free vs Premium

Free protects 1 file per run. Premium removes the limit: protect a whole batch of PDFs with the same password in one pass.