How to password protect your PDF
- 1
Add the PDF you want to protect.
- 2
Type a password twice and choose any restrictions (printing, copying, editing).
- 3
Click Protect PDF and download the encrypted file.
About Password Protect a PDF
Password protecting a PDF encrypts it so that only people with the password can open it. This tool uses AES-256, the strongest encryption in the PDF standard, supported by Adobe Reader, Chrome, Edge, macOS Preview and phone PDF apps.
You can also lock a PDF against printing, copying or editing without requiring a password to open it, which is useful for sharing a report people may read but shouldn’t alter. The encryption runs on your device, so the unprotected file never travels over the internet.
- Send the password through a different channel than the file (for example by text message).
- A long passphrase of three or four words is stronger and easier to remember than a short complex password.
- There is no password recovery: keep it somewhere safe.
Settings explained
- Open password
- Anyone opening the PDF must type it. Use 12+ characters mixing words and numbers.
- Restrictions
- Block printing, copying text, or editing. Restrictions work in standard PDF readers.
- Encryption
- AES-256, the strongest standard PDF encryption, supported by Adobe Reader 9 and later, browsers, macOS and phones.
Private by design
Your file is processed by your own browser, in memory. It is never uploaded, stored or seen by anyone, and the page’s security policy blocks it from sending data to other servers.
Frequently asked questions
How to lock a PDF?
Add the PDF, type a password twice, optionally block printing or copying, then click Protect PDF. The downloaded file asks for the password when opened.
How to take off password protection on PDF?
Open Unlock PDF, add the protected file, type the password and download an unlocked copy.
How secure is the protection?
The file is encrypted with AES-256. With a long, unique password it can’t practically be broken. Weak passwords like “1234” can be guessed, so the strength of the password matters most.
Is it safe to use with confidential documents?
Yes. The file is opened by your own browser and processed in your device’s memory. It is never uploaded, so no server, including ours, ever receives a copy. That makes it suitable for contracts, IDs, medical or bank documents.
Is it really free?
Yes. There is no sign-up, no watermark, no daily limit and no paid tier hiding the useful settings. Because your device does the work, it costs us almost nothing to run.