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IMGFixy Fast • Free • Private
🔒 Cryptographic Security • 100% In-Browser • Zero Server Uploads • Free

Protect PDF (Password Lock)

Encrypt confidential documents with standard cryptographic PDF passwords and enforce granular document permissions for printing, copying, and modifications.

Drop your PDF here, or browse files

Supports single and batch protection. 100% private in-browser encryption.

How to Password Protect and Encrypt PDF Documents Online

Step 1

Upload PDF File(s)

Select or drop confidential PDF contracts, invoices, or bank statements. 100% processed locally in your browser.

Step 2

Set Password & Permissions

Enter a secure open password or generate a high-entropy password. Choose standard or custom permissions.

Step 3

Instant Verified Download

Download the cryptographically protected PDF along with a downloadable Technical Security Audit Report.

Understanding PDF Standard Security & Permission Bitmasks

PDF Standard Security (ISO 32000-1) uses a dedicated `/Encrypt` dictionary containing the Owner Hash (`/O`), User Hash (`/U`), and a 32-bit Permissions Integer (`/P`). Compliant PDF readers (such as Adobe Acrobat, Apple Preview, and Google Chrome) evaluate these bits to enforce restrictions.

🖨️

Printing Control (Bit 3 & 12)

Allows disabling printing completely or restricting print output to low-resolution proofing.

📋

Content Copying (Bit 5)

Controls whether users can select, highlight, and copy text or graphics to the system clipboard.

✏️

Document Editing (Bit 4 & 11)

Restricts altering document content, inserting pages, rotating sheets, or extracting page layouts.

📝

Annotations & Forms (Bit 6 & 9)

Enables or locks interactive form completion, sticky note commenting, and digital signatures.

Frequently Asked Questions (FAQ)

Is the password encryption real or just a website overlay?

It is 100% cryptographic PDF standard encryption. The downloaded file contains encrypted stream objects and an ISO 32000-compliant `/Encrypt` dictionary that standard PDF readers like Adobe Acrobat and Google Chrome will require the password to open.

Are my confidential PDF documents uploaded to any server?

No. All encryption key derivation, object encryption, and verification execute 100% locally in your web browser using WebAssembly and WebCrypto. Your documents and passwords never leave your device.

What happens if I forget the password?

Because standard PDF encryption is mathematically enforced and processed locally without server backdoors, forgotten passwords cannot be recovered. Please ensure you store your password in a secure password manager.

Can I protect multiple PDFs at once?

Yes! You can select or drop multiple PDF documents simultaneously. The tool will encrypt every file and provide a single-click "Download All as ZIP" package.

How does the in-memory verification test work?

Before enabling the download button, the engine reopens the encrypted byte stream in memory: it verifies that opening without password is rejected, wrong passwords fail, and the correct password decrypts and renders Page 1 cleanly.

What is the difference between Document Password and Permissions Password?

A Document Password (User Password) is required simply to open and view the file. A Permissions Password (Owner Password) allows the document creator to modify printing, copying, and editing permissions in Adobe Acrobat.

Will password protecting a PDF affect its visual layout?

No. Encryption secures the file's binary stream without altering fonts, vector artwork, images, or page dimensions.

What is the Technical Security Audit Report?

It is an exportable `.txt` certificate detailing the ISO security parameters, audit UUID, permission bitmasks, encryption version, and verification timestamp for your security records.

Does the tool work on mobile phones and tablets?

Yes. The interface is 100% responsive and touch-friendly, optimized for iOS Safari, Android Chrome, and all modern mobile devices.

Is there any fee or file size limit?

No. IMGFixy Protect PDF is 100% free with unlimited usage, zero subscriptions, and no added watermarks.

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