Password-protect a PDF
Lock your PDF with a password using AES-256 encryption. Optionally restrict printing, copying and editing.
How it works
How to password-protect a PDF
- 1
Open your PDF.
- 2
Enter and confirm a password, and choose permissions.
- 3
Click Protect PDF and download the encrypted file.
Features
Why use our Protect PDF tool
AES-256
The strongest encryption supported by the PDF standard (powered by qpdf).
Permissions
Optionally block printing, copying text or editing.
Never uploaded
Your file and password stay on your device.
Guide
About Protect PDF
Password protection keeps contracts, payslips, medical records and IDs safe in transit and at rest. Anyone opening the file must enter the password, and the contents are unreadable without it.
Encryption uses AES-256 — the strongest method in the PDF standard — via qpdf compiled to WebAssembly. You can also restrict printing, copying and editing for viewers that honour PDF permissions.
Tips for best results
- Use a long passphrase of several words; the strength meter shows how you're doing.
- Send the password through a different channel than the PDF itself.
- We can't recover lost passwords, so keep an unprotected original somewhere safe.
How your file stays on your device
Protect PDF runs entirely inside your web browser. When you choose a file, your browser reads it into memory on your own device, a background Web Worker does the processing, and the result is handed straight back to you as a download. There is no upload step, no server that receives your document and no copy kept anywhere — close the tab and it is gone. That makes it safe for contracts, IDs, medical letters and anything else you would rather not send to a stranger's server. How in-browser processing works
FAQ
Protect PDF: frequently asked questions
What if I forget the password?
We can't recover it — we never see your password or file. Keep a copy of the unprotected original somewhere safe.
Will it open in Adobe Reader and others?
Yes. AES-256 is supported by all modern PDF readers (PDF 1.7 extension level 3 / PDF 2.0).
Are my files uploaded to a server?
No. Encryption happens entirely inside your browser using JavaScript and WebAssembly. Your files never leave your device, and nothing is stored after you close the tab.
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