Protect PDF with Password

Password protect and encrypt any PDF online — add a user open password, set an owner permissions password, and control printing, copying, editing and annotation rights. PDF-lib applies real PDF encryption entirely in your browser. No sign-up, no upload, 100% private.

AESPDF Encryption
2Password Types
5Permission Controls
PrivateNo Upload

Our free PDF password protection tool lets you password protect any PDF online without sign-up or server upload. Upload a PDF, set a user open password so only people with the password can open the document, and optionally set an owner permissions password to control what actions are allowed — printing, copying text, editing content, filling forms, and adding annotations. A real-time password strength meter guides you to choose secure passwords. PDF encryption is applied entirely in your browser using PDF-lib, producing a genuinely encrypted PDF file. Whether you need to secure a PDF before emailing it, lock a PDF document to prevent editing, add password protection to confidential reports, or restrict copying of copyrighted content, this free tool handles real AES-based PDF security with granular permission settings and zero data transmission to any server.

PDF Password Protector & Encryption Tool

Upload PDF › Set passwords › Configure permissions › Apply encryption › Download protected PDF

PDF
Drop a PDF to protect with password
Set user password, owner password and permissions — AES encryption applied in browser
🔒 Your file never leaves your device • 100% private • No sign-up required
Accepts .pdf files • PDF-lib applies AES encryption locally • No server upload
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Pages
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File Size
None
Current Encryption
Unprotected
Status

Ready to protect

Set a password below to encrypt and protect this PDF

User password
Owner password
Permissions set
Passwords At least one required
User Open Password

Required to open and view the PDF. Leave empty to allow anyone to open the document without a password.

Owner Permissions Password

Required to change permissions or remove password protection. Without this, users cannot unlock the restrictions you set below.

Document Permissions Enforced by encryption

Control what users can do with the PDF. These restrictions require an owner password to be overridden. Tick = allowed, untick = restricted.

Encryption Strength
Applying encryption...

How to Password Protect a PDF

01

Upload Your PDF

Drag and drop any PDF onto the upload area or click "Open PDF File". The file is read locally by PDF-lib — your document never leaves your device. Basic file information such as page count and current protection status are shown instantly.

02

Set Passwords & Permissions

Enter a user open password to require authentication before viewing, and/or an owner permissions password to lock down what actions are allowed. Toggle printing, copying, editing, form filling and annotation permissions individually. Choose AES-128 or RC4-128 encryption.

03

Protect & Download

Click "Apply Password Protection" — PDF-lib encrypts the PDF binary using your chosen passwords and settings. A progress bar shows encryption progress. The protected PDF downloads automatically. Open it in any PDF viewer — it will require the password.

PDF Encryption & Security Features

User Open Password

Set a password that must be entered before the PDF can be opened or viewed in any PDF reader. The document remains completely inaccessible without the correct password.

Owner Permissions Password

A separate password that controls whether users can override the permission restrictions you set. Without this password, printing, copying and editing restrictions cannot be bypassed.

AES-128 Encryption

PDF-lib applies AES-128 encryption — the same standard used by Adobe Acrobat. The encryption is applied at the PDF binary level, making the content genuinely unreadable without the password.

Granular Permissions Control

Independently allow or restrict 5 actions: printing, copying text and images, editing and modifying, form filling, and adding annotations. These permissions are enforced by the PDF encryption standard.

Real-Time Password Strength Meter

A live strength indicator guides you to use secure passwords — Weak, Fair, Good, Strong. Colour-coded bar shows password quality based on length, character variety and complexity.

100% Private — No Upload

PDF-lib performs all encryption operations entirely in your browser. Your PDF file and passwords never leave your device — no server, no cloud, no third-party services at any point.

Frequently Asked Questions

How does PDF password protection work technically?
PDF-lib applies AES-128 encryption to the PDF binary using the standard PDF encryption specification. The user password encrypts the file encryption key — without the correct password, PDF viewers cannot decrypt the content streams. The owner password controls a separate permission bit mask embedded in the encrypted PDF structure.
What is the difference between user and owner passwords?
The user password (open password) is required to open and view the PDF — without it the document is completely inaccessible. The owner password (permissions password) is required to override any permission restrictions — printing, copying, editing etc. You can set one, both, or neither (owner-only is useful for permission control without blocking access).
Will the protected PDF work in all PDF viewers?
Yes. AES-128 encryption is the standard PDF encryption method supported by all modern PDF viewers including Adobe Acrobat, Adobe Reader, Preview on macOS, Chrome PDF viewer, Edge, and all major mobile PDF apps. For maximum compatibility with legacy viewers (pre-2004), choose RC4-128 mode.
Is this tool completely free?
Yes, 100% free. No sign-up, no subscription, no watermarks on the output PDF. PDF-lib performs all encryption in your browser — there is no server processing, no API calls, and no usage limits.
Is my PDF and password private?
100% private. Your PDF file never leaves your device. Your passwords are never transmitted to any server. PDF-lib encrypts the document entirely within your browser using local JavaScript execution — nothing is sent to Tooll.live or any third party.

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