Protect PDF with a Password
Drag & drop a PDF here, or click to browse
Up to 100 MB · Processed entirely in your browser via QPDF (WebAssembly)
Selected file
Loading the encryption engine…
How it works
This tool uses QPDF, the widely-used open-source PDF library, compiled to run directly in your browser. Encryption is real AES-256, applied by QPDF's own code — nothing is uploaded, and the encryption engine only downloads (about 1.3 MB) the moment you actually protect or unlock a file.
Frequently asked questions
Is this real password protection?
Yes. It uses AES-256 encryption applied by QPDF, the same open-source library used in many production PDF pipelines — not a simulation.
What if I forget the password?
There is no recovery. AES-256 cannot be reversed without the password, so keep a copy somewhere safe.
Is my file uploaded anywhere?
No. Both protecting and removing a password happen entirely in your browser.
Password-protecting a PDF used to mean uploading it to a website and trusting that site with the file, or installing desktop software. This tool runs QPDF \u2014 the same open-source engine widely used in production PDF pipelines \u2014 directly in your browser via WebAssembly, so the encryption is real AES-256 and the file never leaves your device.
