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ToolNest AI
Free

Protect PDF

Protect PDF files with a password and encryption online for free.

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Drag & drop your PDF here

or click to browse — PDF only · up to 200 MB

Password protectionRC4-128 encryptionPermission controlsBrowser-localFree

How it works

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1. Upload

Drop your PDF — it stays in your browser

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2. Set password

Enter a user password and confirm it

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3. Permissions

Choose which actions to allow or deny

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4. Protect

Download your RC4-128 encrypted PDF

About Protect PDF

Upload any PDF and add a user password (required to open the file) and an optional owner password (controls permissions). Restrict printing, text copying, editing, annotations, and form filling independently. All encryption is handled in-browser by pdf-lib — no files leave your device. The result is a standard password-protected PDF compatible with Adobe Reader, Preview, and all major viewers.

Frequently Asked Questions

Upload your PDF, enter a user password (the password that will be required to open the file), confirm it, then click Protect PDF. The encrypted PDF downloads automatically.

Yes. Set an owner password and use the permissions toggles to allow or disallow printing, copying text, editing, annotations, and form filling. Viewers need the owner password to override these restrictions.

Yes. Your file never leaves your device. All encryption is performed in your browser using pdf-lib — no data is uploaded to any server.

pdf-lib applies RC4-128 encryption, the same algorithm used by standard PDF password protection. The resulting file is compatible with all major PDF viewers including Adobe Acrobat, Preview on macOS, and browser-based PDF viewers.

Yes, completely free with no account required and no usage limits.

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