Protect PDF
Free·No signup·Files never leave your device
How to password-protect a PDF in 3 steps
Real encryption, applied in your browser: a password to open, and permissions that travel with the file.
Upload the PDF
Drop the document in the box above. Encryption happens locally — even the password stays on your device.
Set password and rules
Choose the open password, then optionally restrict printing, copying, or editing.
Download the locked file
Click Protect. The encrypted PDF downloads immediately, ready to share safely.
Why protect PDFs with AmiPDF
Standard PDF encryption without handing the document to a server.
Private by design
Processing happens entirely inside your browser. Nothing is uploaded, stored, or shared — ever.
No signup, no watermark
No account, no email, no limits. Your output comes out exactly as your files went in.
Granular permissions
Beyond the open password, control whether recipients can print, copy text, or modify — enforced by every compliant PDF reader.
Works on any device
The same fast experience on Windows, Mac, Linux, Android, and iOS — no installation.
When to password-protect a PDF
Tax documents sent by email, legal drafts shared with counterparties, employee records passed between systems, exam papers distributed early. A password turns an open letter into a sealed envelope.
Encryption runs on your device — the unencrypted file and the password both stay local.
Password-protect PDFs on any platform
AmiPDF runs in your browser — nothing to install, nothing to configure, nothing to update.
Windows
Chrome, Edge, Firefox
macOS
Safari, Chrome
Linux
Any modern browser
iOS
Safari on iPhone, iPad
Android
Chrome, Samsung Internet
Frequently asked questions
What encryption does AmiPDF use?
Standard PDF encryption (AES) — the same mechanism Acrobat and every mainstream reader support. Protected files open anywhere with the password.
What's the difference between the two passwords?
The open password is required just to view the file. The permissions password (optional) guards the restriction settings — recipients can read freely but need it to change permissions.
Can restrictions be bypassed?
Permissions are enforced by compliant readers, which covers the tools people actually use. Determined users with special software can strip them — treat permissions as a strong lock, not a vault.
I forgot the password. Can you recover it?
No — and that's the point of encryption. We never see your password; it exists only in your head and your browser session. Keep a copy somewhere safe.
Does protection change my document's content?
No. Pages, text, and images are untouched; only the file's security envelope changes.
Is my password sent to a server?
Never. Both the file and the password stay in your browser; only the encrypted result is written for download.
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