How to password-protect a PDF
Sending a contract, payslip or medical letter as an open PDF means anyone who intercepts it can read it. Adding a password takes seconds and means only the person you give it to can open the file.
Drag and drop here, or choose from your device.
Up to 50 MB per file. Files are processed in your browser.
Full options and FAQs on the PDF Password Protection page.
What PDF protection actually does
An open password encrypts the document: without the password the file is unreadable, not just gated by a warning screen. That is the protection you want before emailing anything sensitive. Because the tool below works in your browser, the document and the password never travel to a server to be processed.
Choosing a password that survives
- Use at least 12 characters — a short password can be brute-forced offline.
- Avoid the obvious: the recipient's name, the company, 'invoice2026'.
- A phrase of three unrelated words is both strong and easy to dictate.
- Never reuse the password you use for email or banking.
The step everyone forgets
Send the password by a different channel than the file. A password in the same email as the PDF protects nothing — anyone reading the mailbox has both. Text or call the recipient with the password, and email the file. Keep a record of the password yourself; there is no recovery option on an encrypted PDF.
Step by step
- 1Add your PDF to the protection tool below.
- 2Enter a strong password — twelve characters or more.
- 3Apply the protection and download the encrypted copy.
- 4Send the file by email and the password by a separate message.
- 5Store the password somewhere safe; it cannot be recovered.
Frequently asked questions
- Can a password-protected PDF be cracked?
- Weak passwords can be guessed by automated tools, which is why length matters. A long, unique password makes offline attacks impractical for ordinary documents.
- Will the recipient need special software?
- No — every PDF reader, on phones and computers, can open a password-protected PDF. They just type the password.
- Can I remove the password later?
- You would need the password and a tool that can re-save the file unlocked — so keep an unprotected original if you will need one.