Is the encryption real?

Yes. HivePDF encrypts your PDF with AES-256 using qpdf — the same standard encryption that professional tools use. It's not a fake “viewer lock”; the file's contents are genuinely encrypted.

Does my file or password get uploaded?

No. The encryption runs entirely in your browser with WebAssembly. Your PDF and your password never leave your device — there's no server involved.

What if I forget the password?

There's no recovery. Because the encryption is real and we never see your password, a lost password means the file can't be opened. Store it somewhere safe.

What do the restrictions do?

They mark the PDF so that opening it with your password still won't allow printing, copying text, or editing, depending on what you tick. Note that enforcement depends on the PDF reader respecting these flags.

Password Protect PDF Free — AES-256 Encryption

Drop a PDF here or click to select

Files never leave your device.How it works

How to password protect a PDF

1Drop your PDF above (or click to select).
2Type a password to open the file, then confirm it. Optionally tick restrictions like no printing or copying.
3Click Protect, then download the encrypted PDF.

Frequently asked questions

Is the encryption real?: Yes. HivePDF encrypts your PDF with AES-256 using qpdf — the same standard encryption that professional tools use. It's not a fake “viewer lock”; the file's contents are genuinely encrypted.
Does my file or password get uploaded?: No. The encryption runs entirely in your browser with WebAssembly. Your PDF and your password never leave your device — there's no server involved.
What if I forget the password?: There's no recovery. Because the encryption is real and we never see your password, a lost password means the file can't be opened. Store it somewhere safe.
What do the restrictions do?: They mark the PDF so that opening it with your password still won't allow printing, copying text, or editing, depending on what you tick. Note that enforcement depends on the PDF reader respecting these flags.

A password that actually protects the file

Password-protecting a PDF should mean the file is encrypted — not just that a reader politely hides it. HivePDF encrypts your document with AES-256, the current standard, using the open-source qpdf engine compiled to WebAssembly. Without the password, the bytes are unreadable. And because it all runs in your browser, the one thing you never want to upload — a confidential file plus its password — never leaves your device.

Open password and optional restrictions

The main setting is a password required to open the document. On top of that, you can add restrictions: prevent printing, prevent copying text, or prevent editing. These are enforced by a separate owner password that HivePDF generates randomly and discards, so the restrictions hold even for someone who knows the open password.

Good to know

Keep your password somewhere safe — the encryption is real, so a forgotten password can't be recovered by us or anyone else. If you later need to remove the password, use Unlock PDF with the password you set. To protect a file you've already merged or organized, do those steps first, then protect the final PDF.

Why AES-256 and qpdf

qpdf implements the PDF encryption standard the same way Adobe Acrobat does, so a file protected here opens correctly, password prompt and all, in any compliant PDF reader — not just HivePDF. That interoperability matters: a homegrown lock that only your own tool understands isn't real protection.

When to reach for something else

A password stops casual access, but it won't stop someone determined and technical from attacking a weak password offline, so use a long, random one for anything sensitive. If you need to black out specific content rather than lock the whole file, that's a job for redaction, not encryption.

Password protect a PDF