PDF Tools

PDF Protect – Encrypt PDF Files with a Password (Client‑Side & Private)

Add a password to your PDF with AES-256 encryption, then download the protected copy.

Use this free PDF protect tool to encrypt a PDF and password protect it in your browser. Your file and your password stay on your device, so nothing is ever uploaded.

PDF and password stay on your device

Drop a PDF here, or choose one.One PDF at a time, up to 100 MB.

Your PDF and password stay on your device. Nothing is uploaded.

Protected PDF
Your protected PDF will appear here...

How PDF Encryption Works

Encryption scrambles the contents of a PDF so it can only be read with the right key. Your password is used to create that key. This tool encrypts every page with AES-256, the standard used by modern PDF software, and saves a new copy. Viewers ask for the password before showing anything.

1. Add your PDF

Drop the file onto the upload area or choose it from your device. The tool checks that it is a real PDF that isn't already locked.

2. Choose a password

Type a password and confirm it. A simple strength guide helps you pick one that is hard to guess.

3. Download the encrypted copy

The tool encrypts every page and saves a new PDF that asks for the password to open. Your original file is never changed.

Password Requirements

Choose a password you can remember and others can't guess. The checks are basic: a minimum length and matching boxes. The strength guide is advice only, so it never blocks you. Use the show/hide button to check what you typed.

Basic rules

Use at least 6 characters, up to 100. Both boxes must match. Passwords are case-sensitive, so capital letters count.

Make it strong

Longer is better. Aim for 12 or more characters, or a few unrelated words, and avoid names, dates and common passwords.

Don't lose it

There is no reset. Nobody, including this site, can recover a forgotten password, so keep it somewhere safe.

Encrypt a PDF Without Uploading It

Everything happens in your browser. Your PDF and its password are processed on your own device, so neither is uploaded, logged or stored on a server. That matters for contracts, bank statements, ID scans and other documents you wouldn't want to send to a stranger's website. Close the tab and nothing is left behind.

Supported PDF Types

Standard PDFs

Documents, contracts, forms, reports and e-books saved as PDF, up to 100 MB each.

Scans and images

Scanned documents and photos saved as PDF work too, and pages keep their original quality.

Not already locked

A PDF that already has a password can't be protected again. Remove the old password with PDF Unlock first.

Works on Mobile and Desktop

The tool works in any modern browser on phones, tablets and computers, with nothing to install. On a touchscreen, the password boxes use a comfortable text size, so your phone won't zoom in, and the show/hide button is easy to tap. On a computer, you can drag a PDF straight onto the upload area.

Frequently Asked Questions

How do I password protect a PDF?
Add your PDF, type a password twice, and click Encrypt PDF. When it finishes, download the new file. It will ask for the password every time someone opens it.
What kind of encryption does it use?
AES-256, the strongest standard encryption available for PDFs. It is supported by current versions of Adobe Acrobat, Chrome, Edge, Firefox, Safari and Preview, and by most phone PDF apps.
Is my PDF or password uploaded anywhere?
No. The PDF is encrypted in your browser, on your own device. Neither the file nor the password is uploaded, logged or stored, so it is safe to use with private documents.
What if I forget the password?
It can't be recovered. The password is the only key, and it isn't saved anywhere. Keep it in a password manager or another safe place.
Does encryption change how my PDF looks?
No. Pages, text, images and links are copied across unchanged, and the file size stays about the same. The only difference is that it now needs a password to open.
Can I protect a PDF that already has a password?
Not directly. Use PDF Unlock to remove the old password, then protect the file again with a new one.
Does it work on my phone?
Yes. The password boxes and the show/hide button are sized for touch, and the whole tool runs in your mobile browser with nothing to install. Very large PDFs may take longer on older phones.