Protect PDF
Add password protection to your PDF
How it works
Upload your file
We process it instantly in your browser
Download your result in one click
Your files stay private. All processing happens locally in your browser. Files are never uploaded to any server.
How to Use Protect PDF
Adding a password to a PDF is the fastest way to ensure only authorized people can open it. Whether you're sharing a confidential contract, a personal tax return, or a sensitive report, encryption means the file is useless to anyone who intercepts it without the password. PDF Mate encrypts your document locally with AES-256 — no file is ever uploaded.
- 1
Upload your PDF
Click "Select File" or drag your PDF into the upload area. The file is read locally — it is never sent to any server.
- 2
Set a password
Enter a strong password in the password field. Use a mix of letters, numbers, and symbols. The password will be required to open the document.
- 3
Choose permission settings (optional)
Optionally restrict what readers can do: prevent printing, copying text, or editing. These restrictions are enforced by PDF viewer applications.
- 4
Encrypt and download
Click "Protect PDF." The tool applies AES-256 encryption and downloads the protected file to your device. Store your password safely — there is no way to recover it if lost.
Pro Tips
- ✓Use a password you will remember — or store it in a password manager. A lost PDF password cannot be recovered without specialized software.
- ✓AES-256 encryption (used here) is the same standard used by governments and financial institutions. A strong password makes it practically unbreakable.
- ✓Permission restrictions (no printing, no copying) add a layer of control, but determined users with the right tools may bypass them. For truly sensitive documents, strong encryption is the real protection.
- ✓If you are distributing the PDF to multiple people, consider using a different password for each recipient so you can revoke access individually.
- ✓Always keep an unprotected backup of your original PDF in a secure location.
The encrypted PDF is downloaded directly to your device. PDF Mate never stores your document or your password — encryption happens entirely in your browser.
Frequently Asked Questions
What type of encryption does PDF Mate use?
AES-256 encryption — the industry standard used by banks, governments, and security software. It is virtually unbreakable with a strong password.
Can I restrict printing or copying without setting an open password?
Yes. You can set permissions-only restrictions with a separate owner password that is different from the open password. This lets recipients open the document freely but prevents specific actions.
What happens if I forget the password?
PDF passwords cannot be recovered without the original password. There is no back door. Keep your password in a secure password manager.
Can I protect a PDF that is already password-protected?
No — you must unlock the PDF first, then re-protect it with a new password.
Will permission restrictions prevent all editing?
Permission restrictions are honored by standard PDF viewers (Adobe Reader, Preview, etc.). They are not a substitute for strong encryption — advanced tools can bypass permission flags. Encryption is what truly protects the content.
Is my PDF uploaded to a server to be encrypted?
No. Encryption runs entirely in your browser using WebAssembly. Your document never leaves your device — this is critical for legal contracts, medical records, and financial statements.
Can I remove the password later?
Yes. Use the Unlock PDF tool with the correct password to remove protection from the file.