Question 1

How do I password protect a PDF for free?

Accepted Answer

Upload your PDF, enter a password, and click Lock PDF. The encrypted PDF downloads to your device.

Question 2

What encryption is used to protect the PDF?

Accepted Answer

PDFs are encrypted with 128-bit RC4 encryption, compatible with all major PDF viewers.

Question 3

Will I lose any content when locking the PDF?

Accepted Answer

No. Only encryption is applied — all content and pages remain exactly as they are.

Question 4

Are my files uploaded when adding a password?

Accepted Answer

No. Encryption is applied entirely in your browser using PDF-lib.

Question 5

Can I set different passwords for opening and editing?

Accepted Answer

The current tool sets a single document open password. Advanced permission passwords are not yet supported.

Lock PDF

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