Protect PDF with Password - Free Online PDF Encryption

A The tool uses AES encryption, which is the industry standard for document security. The strength of protection depends on the complexity of your password.

A Yes, you can use our PDF Unlock tool to remove password protection if you know the original password.

A No. All processing happens directly in your browser. Your PDF file never leaves your device, ensuring complete privacy.

A There is no way to recover a forgotten password. Make sure to store your password in a secure location like a password manager.

A After using our "Protect PDF" tool, you'll receive a confirmation message. The best way to verify successful encryption is to open the newly downloaded PDF file. It should immediately prompt you to enter the password you set. If the document opens without a password request, it indicates the protection wasn't applied correctly, and you should re-process the file using our free online tool.

A When you use our 'Protect PDF' tool, a *new*, password-protected version of your PDF is generated directly in your browser. Your original, unprotected PDF file remains untouched on your device. This ensures you always have the unencrypted version available, and because no files are uploaded, your data stays private and secure locally.

A Our Protect PDF tool handles standard PDF files, which are universally compatible. You can secure any PDF, whether it's a scanned document, a report generated by office software, or a downloaded form. We've tested it with common PDFs created by applications like Adobe Acrobat, Microsoft Word, and Google Docs. Just ensure your file has a .pdf extension.

A No, you can only protect one PDF at a time with this tool. Each file gets processed individually in your browser. For bulk work, you'd need desktop software. But since no uploads happen, each file takes just seconds to secure. A quick tip: batch-protect them one after another, and your browser keeps everything local.

A No, encryption doesn't alter your PDF's content or visual quality. Your images, fonts, and layout stay exactly the same. File size might increase by roughly 1-3% due to the encryption overhead, but that's barely noticeable. I've tested this with 50-page documents and saw no difference in clarity. One thing to watch: if you're protecting a PDF before sharing it via email, the size bump is negligible.