Protect / Unlock PDF
SecurityEncrypt a PDF with a password, or remove a known password from a protected PDF. All processing stays in your browser.
How to use Protect / Unlock PDF
- Open this page in any modern web browser — no download or installation required.
- Click Add file or drag and drop your PDF onto the drop zone.
- Adjust the available settings to fit your needs.
- Click the action button and save the processed file — the result is ready instantly.
Files never leave your browser. No upload to any server.
Processing runs locally on your device. No queues, no waiting.
No signup, no watermarks, no limits. Use as many times as you like.
Why use Protect / Unlock PDF on PDF Modern?
PDF Modern’s protect / unlock pdf tool processes your file entirely within your web browser using modern WebAssembly technology. Unlike traditional online PDF services that require uploading your documents to remote servers, your files never leave your device — ensuring complete privacy and security. Processing happens at the full speed of your CPU, not limited by upload or download bandwidth, so even large files are handled in seconds. There are no file-size restrictions, no daily usage caps, no watermarks on output, and no account creation needed. It is a fully free, open tool built for everyday document workflows at home, school or the office.
Frequently asked questions
How strong is the encryption?
PDFs are encrypted with AES-256 (industry standard).
Can I unlock a PDF I forgot the password to?
No. You must know the password — this tool does not crack passwords.
Are my files uploaded?
No. Encryption and decryption run entirely in your browser.