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Upload a PDF to add real AES password protection, or remove a password you already know — using the QPDF engine, compiled to run entirely in your browser.
Lite PDF Suite
Protect & Unlock PDF
Protect and Unlock PDF Guide
Protecting a PDF means adding a real password so only someone who knows it can open the file, while unlocking means removing a password from a file when you already know it and no longer need the restriction. Lite PDF Suite's protect and unlock tool applies genuine AES encryption when you add a password, the same standard used by professional document security software, all processed inside your browser so your password and file are never sent anywhere. This is different from tools that simply hide a warning message, since a properly encrypted PDF cannot be opened by any PDF reader without the correct password being entered first. That real encryption is what makes the tool suitable for documents that genuinely need to stay private, not just documents that look password protected.
Key Features
The tool covers both sides of PDF security in a single place, so you never need a separate program for the opposite task.
- Real AES password protection: lock a file with genuine encryption, not a cosmetic restriction.
- Password removal: unlock a file you already have the password for, instantly.
- Open password support: require a password just to open and view the file.
- Fast local processing: encryption and decryption both happen in your browser.
- No password storage: your password is used only in the moment and never saved anywhere.
- Works with existing encrypted files: unlock PDFs that were password protected using other software.
How to Use It
Locking or unlocking a file only takes a password and a click, with no additional configuration required.
- Upload the PDF you want to protect or unlock.
- Choose whether you want to add a password or remove an existing one.
- Enter the password to apply, or the password to remove it.
- Let the tool process the file locally in your browser.
- Click Download to save the protected or unlocked PDF.
Because processing happens on your device, even large files are secured or unlocked within seconds. The resulting file works normally in any standard PDF reader that supports password protection.
Common Use Cases
Password protection matters whenever a document should only be seen by specific people, or when a restriction is no longer needed.
- Protecting a sensitive contract or financial statement before emailing it.
- Locking a file containing personal identification before sharing it online.
- Removing a password from an old file once the restriction is no longer needed.
- Securing HR documents such as offer letters or salary details.
- Adding a password to a shared report before distributing it to a wider audience.
- Protecting a scanned copy of an identity document before storing it.
Frequently Asked Questions
Is adding or removing a password free? Yes, both protecting and unlocking PDFs on Lite PDF Suite are completely free.
Is my password ever stored or sent anywhere? No, the password is used only during local processing and is never saved or transmitted.
What encryption standard is used? The tool applies real AES encryption, the same standard used by professional PDF security software.
Can I unlock a file if I do not know the password? No, unlocking requires the correct existing password, since the tool does not attempt to bypass security.
Will a protected file still open in other PDF readers? Yes, any standard PDF reader will prompt for the password since the encryption follows the normal PDF format.
Not every document needs a password, but the ones that do usually contain information you genuinely cannot afford to expose, such as financial records, legal agreements, or personal identification. Lite PDF Suite's protect and unlock tool takes that responsibility seriously by applying real encryption rather than a cosmetic restriction that only looks secure. Because both locking and unlocking happen entirely on your device, your password is never transmitted or stored anywhere, which means the security of the file depends only on how carefully you handle the password itself, not on trusting an outside server.
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