PDF Tools·6 min read·September 12, 2026

How to Password Protect a PDF

Add a password to a PDF so only the right people can open it. A clear guide to encrypting a PDF online, plus how to pick a strong password.

Why protect a PDF

Contracts, payslips, medical letters and ID documents often travel by email, where copies can be forwarded or land in the wrong inbox. A password encrypts the file so that without it the contents are unreadable, which is the simplest way to keep a sensitive document private in transit and at rest.

Add a password to your PDF

Open the Protect PDF tool, upload the file, set a password, and download the encrypted PDF. Anyone who opens it afterwards will be asked for that password. Send the password separately from the file, for example by message rather than in the same email, so a single intercepted message does not expose both.

Choose a strong password

Use at least 12 characters mixing upper and lower case, numbers and symbols, and avoid names, dates or dictionary words. A short memorable phrase with a few substitutions is both strong and easy to recall. Never reuse an important password across files and accounts.

Open password vs permissions

An open password is required just to view the document. A permissions password instead allows opening but restricts actions like printing, copying text or editing. Choose an open password when the content itself must stay private, and permissions when you want people to read but not alter or extract it.

Removing protection later

If you own the file and know the password, you can remove it with an Unlock PDF tool when you no longer need the restriction, for instance before archiving an internal copy. Keep the password stored safely in a password manager, because an encrypted PDF cannot be recovered if the password is lost.

A note on privacy

Because protection is applied in the browser where possible, your document is not uploaded to a server to be encrypted, so the sensitive file you are trying to secure does not sit on someone else’s machine during the process.

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