Password protect PDF files online

Turn on Also restrict editing before you click Protect PDF. Then pick what people can do with the file once it's open:

• Printing: allowed, low quality only, or not allowed
• Copying text and images
• Editing the content
• Adding comments and filling in forms
• Adding or removing pages

When you turn it on, printing stays allowed and everything else is blocked. Change any choice to suit the file, such as allowing form filling on an application form.

Want anyone to be able to read the file, but not change it? Choose Lock only. The PDF then opens without a password, and the limits you picked still apply.

Most PDF apps respect these limits, but some tools can remove them. Limits control what people do with a file, not who can read it. For private files, use a password to open, which encrypts the content.

Change the limits later with an owner password

The limits are guarded by a second password, called the owner password. Leave it empty and a random one is made and never shown. That way, your password to open can't be used to lift the limits.

Set your own owner password if you want to change the limits later. Keep it different from your password to open.

A password to open encrypts your PDF with AES-256. The pages, text and images are scrambled, and only the right password turns them back into a readable file. The title and author are encrypted too.

AES-256 is the current standard for PDF encryption. The PDF 2.0 standard marks the older 128-bit methods as out of date. So this tool always uses AES-256, with no weaker setting to pick by mistake.

The encryption is only as strong as your password. A short or common password can be guessed, so:

• Use at least 12 characters. Length matters more than anything else.
• Mix words, numbers and symbols, and avoid names and birthdays.
• Don't reuse a password from your email, bank or other accounts.
• Or use the generator. One click fills both fields with a random 16-character password.

The strength meter rates your password as you type, based on its length and its mix of characters. Accented letters and other alphabets work too.

Save the password somewhere safe before you share the file. Nobody can recover a lost password, including us.

See what your protected PDF got

After you click Protect PDF, the tool reads the new file back and shows what it has: AES-256 encryption, whether it needs a password to open, and which actions are allowed or blocked. You can check it before you send the file.

Protect the PDF here, then attach the protected copy to your email like any other file. Send the password a different way. Follow these steps:

• Add a password to the PDF and download it.
• Attach the protected file, named like invoice-protected.pdf, to your email.
• Send the password in a text message, or tell the person in a phone call.

Don't put the password in the same email. If someone else gets into that inbox, they get the file and the password together.

Is the file too big to attach? Compress the PDF first, then protect it. Adding a password doesn't make a PDF smaller, so shrink it before you protect it.

This tool is free, with no sign-up, no usage cap and no watermark. You don't need paid PDF software or an app. Your PDF is protected on your phone or computer, and it never leaves your device.

• It works in the browser on Windows, Mac, iPhone and Android.
• Protect up to 20 PDFs at once, up to 100 MB each, with one password. They download together in one ZIP.
• Each protected file keeps your PDF's name, like report-protected.pdf.
• Your pages, text, images and form fields stay as they are.
• Your password isn't saved or sent anywhere.
• A PDF that's already protected can't be protected again here. Remove its password first, then add a new one.