PDF Tools
Protect PDF
Add a password to a PDF with AES-256 encryption — entirely in your browser. The file and your password are never uploaded. No account, no email.
Frequently asked questions
- Does my file or password get uploaded?
- No. The encryption runs entirely in your browser, on your own device. The file never leaves your computer, and the password is never transmitted — it exists only in your browser's memory while the encryption runs.
- What encryption does it use?
- AES-256 — the same standard used in Acrobat and other professional tools. The output is a standard password-protected PDF that opens in any PDF reader: Acrobat, Chrome, Preview, and others.
- What happens if I forget the password?
- Because the encryption runs on your device and we never see the password, we have no way to recover it. Keep the password somewhere safe before encrypting.
- How is this different from iLovePDF or Smallpdf?
- Both upload the file and the password to their servers to encrypt it — handing both halves of the secret to a stranger. Filum encrypts entirely in your browser: the file and password never leave your device.