# 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 — what we do not do

This tool runs entirely in the browser via WebAssembly. Your file never reaches a Loft Tools server. Specifically:

- **No upload.** The file bytes load into the browser tab's memory and process on your own CPU. Open DevTools → Network and observe zero outbound requests carrying file data while Protect PDF with Password runs.
- **No AI training on your file.** Loft does not train models. We could not train on a file we cannot see.
- **No content scanning.** No virus, copyright, or content-moderation pass against your file. The bytes are not accessible to us.
- **No server-side log of file contents, filenames, or EXIF metadata.** Cloudflare edge captures URL and truncated IP for abuse defense (standard CDN behaviour). Cloudflare Web Analytics records anonymous page hits, no cookies, no PII. Nothing about your file content reaches any log.
- **No retention.** Close the tab and the file leaves browser memory. No backups exist on our side because no copy ever existed on our side.
- **No account.** No email, no signup, no auth, no telemetry tied to you.
- **Offline-capable after first visit** (PWA). Once you've loaded a tool, it caches; later sessions work without internet. For high-sensitivity files, run the tool once online to warm the cache, then disconnect before processing.

Compare with upload-based services: each transmits your file to a processing server. Even over HTTPS, each has logs, retention windows, and subpoena exposure. Loft has none of these because the server architecture does not include your file.

## More

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