Free & Fast — No server uploads, no installs, no watermarks.
Drop your PDF here or click to browse
Maximum file size: 100MB
🔒 By using this tool, you confirm you own or have permission to encrypt this file.
Your file is processed locally and never uploaded.
The Password Protect PDF tool encrypts your PDF files with AES-256 encryption — the same standard used by banks, governments, and military organizations worldwide. This is true encryption, not just a password prompt.
Unlike many online PDF tools that upload your files to remote servers, this tool processes everything directly in your browser using WebAssembly technology. Your sensitive documents never leave your device, ensuring complete privacy.
AES-256 encryption is considered extremely secure with current technology. For a strong, random password, even the world's most powerful publicly known computers would not be able to brute-force it in any reasonable timeframe.
While we use strong, modern encryption techniques, no security measure is perfect. Always follow your organization's security policies and best practices.
Is this tool legal to use?
Yes, when used on files you own or have permission to encrypt. You may only use this tool for lawful purposes and on documents you have the right to protect. This tool is designed to help you protect your own documents before sharing them.
Is my PDF really encrypted, or just password-prompted?
This tool applies true AES-256 encryption to your PDF content. The actual data is scrambled and unreadable without the correct password. You can check your PDF's security using our verification tool.
What encryption standard does this use?
AES-256 (Advanced Encryption Standard with 256-bit keys). AES-256 is widely used by governments, banks, and large organizations for highly sensitive data.
Is this tool safe to use for sensitive documents?
Yes. All processing happens in your browser. Your files are never uploaded to any server. The encryption engine runs entirely on your device using WebAssembly.
What if I forget my password?
There is no way to recover a forgotten password. AES-256 encryption is designed to resist brute-force attacks with current technology, so there's no practical way to recover a lost password.
Does this work on mobile devices?
Yes, this tool works on all modern browsers including Chrome, Safari, Firefox, and Edge on both desktop and mobile devices.
Is there a file size limit?
For best performance, we recommend files under 100MB. Larger files may work but could be slower depending on your device.