Protect PDF
Add a password so the PDF cannot be opened without it.
When to use it
Use it before sending a PDF with personal, financial or medical details by email or through a cloud folder.
How it works
- Choose a file, or drop it onto the box above.
- Enter a password twice. The PDF is encrypted with AES-256 in your browser; choose whether printing and copying are allowed once it is opened.
- Press the Protect PDF button.
- Download the result, or add a next step without downloading.
Supported formats
- Input
- Output
- Files
- One file at a time
Where your file goes
This tool runs in your browser: the file is processed on your device and is not uploaded. The Network tab of your browser's developer tools shows this.
What is kept, and what is not
Everything in the document is kept. We never see or store the password — if you forget it, nobody can recover the file, including us.
Limits
- If the password is lost, the file cannot be opened again. Keep the password somewhere safe.
- Files up to 512 MB each.
- PDF documents up to 5,000 pages.
- The work happens in your device's memory, so a phone may fail on a file that a computer handles.
If something goes wrong
The protected file still opens without a password
Check that you opened the new file you downloaded, not the original you added.
The PDF asks for a password
Remove the password first with Unlock PDF (you need to know it), then try again.
The page becomes slow with a very large file
Close other tabs, or use a computer instead of a phone.
My file is not accepted
Check the formats listed above. A damaged file, or one with the wrong extension, is refused with a message saying why.
Questions
What do the printing and copying options do?
They tell PDF readers whether someone who has the password may print the document or copy its text.
Is the password sent to a server?
No. The file is encrypted in your browser, and the password is not stored by this site.