Protect a PDF with a Password, Free
Make sure only people who know the password can open your file
🔒 No upload • No account • No watermark • Runs in your browser
Protect PDF locks a document with a password. Text and quality are left untouched, and the encryption is applied on your device.
How to use Encrypt PDF
- Select your PDF.
- Type a password twice.
- Press Encrypt PDF.
- Download the protected copy and share the password separately.
Features
- Password required to open the file.
- No change to text, fonts or images.
- Your password never leaves your browser.
- No account needed.
Good to know
- A forgotten password cannot be recovered, so store it safely.
- Standard PDF protection suits everyday privacy. It is not a replacement for specialist security tools.
Questions and answers
Which password should I choose?
A long phrase of several words is stronger than a short word with numbers.
Can I remove the password later?
Yes, with Unlock PDF, as long as you know the password.
Does protecting a PDF make it larger?
Only slightly.
Privacy
This tool runs inside your browser. Your file is read into your device’s memory, processed there and handed back as a download. It is not sent to a FirePDF server. You can test this by switching off your internet connection after the page has loaded and running the tool again. Read the Privacy Policy and the Security page for details.
Want more background? Read the step-by-step guide.