Password Protect a PDF — Free, No Upload
How it works — 100% in your browser, no upload
Drop a PDF here to protect it
Encrypted locally with AES-256 — the file never leaves your device.
Strength: Empty
The password is held only in this tab while you work and is never sent, saved or logged. If you lose it, the document cannot be opened again.
How to password protect a PDF
- Add the PDF. Drop or select the document you want to lock.
- Set a password. Type the open password and confirm it. Twelve characters or more is safer.
- Choose permissions. Decide whether printing, copying, editing and comments stay allowed.
- Download. Save the protected copy. Opening it now asks for the password.
Frequently asked questions
Is my PDF or password uploaded anywhere?
No. The encryption runs in your browser tab with WebAssembly-free JavaScript. The document is read into memory, encrypted and written back to a download — no server, no storage, no logging of the password.
How strong is the encryption?
AES-256, the strongest cipher defined by the PDF standard (ISO 32000-2). Every modern reader — Acrobat, Preview, Chrome, Edge — can open the result with the password.
Can I recover the password if I forget it?
No. Nothing is stored on our side, so there is no reset. Keep the password in a password manager before you close the tab.
Can this remove a password from a PDF?
No. This tool only adds protection. If a document is already encrypted it will tell you and stop, so a protected file is never silently re-written.
What is the owner password for?
The open (user) password is required to view the file. The optional owner password unlocks full rights, so you can keep editing while others are limited to the permissions you chose.
Related tools
Need smaller files? Use the FileSlim compressor or browse all free tools.