# Protect PDF with Password

> Add password protection and encryption to PDF files. Restrict printing, copying, and editing. Keep the original. This tool downloads a clean copy alongside it.

Live tool: https://lofttools.com/tools/pdf-tools/protect-pdf

Category: PDF & Documents

## How it works

1. **Select PDF** — Drop the PDF you want to encrypt, or click to browse
2. **Set password** — Enter a password and choose permission restrictions
3. **Download** — Download your protected PDF instantly

## FAQ

### What encryption level is used?

AES-256 encryption is used, the same standard used by banks and governments.

### Does this preserve bookmarks and form fields?

Yes. Encryption only adds password and permission flags; bookmarks, form fields, and annotations are kept verbatim.

### What PDF versions are supported?

Encryption works on PDF 1.0 through 2.0. The output uses AES-256 (PDF 2.0) or AES-128 (PDF 1.7) depending on the chosen security level.

## Privacy

This tool runs entirely in the browser. Files are not uploaded to a server. They never leave the user's device.

## More

- All tools: https://lofttools.com/tools
- Category: https://lofttools.com/tools/pdf-tools
- LLM index: https://lofttools.com/llms.txt