# Password Protect PDF

URL: https://pdfflare.com/tools/pdf/password-protect-pdf
Category: PDF Tools

Add password protection to PDF files online for free. Encrypt your documents with RC4 128-bit security — 100% browser-based, no upload needed.

## What it does

Password Protect PDF Online — Free & Secure. Encrypt PDF with password.

Runs entirely in your browser. No file ever uploads to a server unless the tool explicitly requires server-side processing (LibreOffice for Office formats, Ghostscript for PDF compression). Free to use, no signup, no rate limits.

## Common search queries this tool answers

- password protect pdf online
- encrypt pdf
- lock pdf
- pdf password
- secure pdf
- add password to pdf

## How to use it

1. Open https://pdfflare.com/tools/pdf/password-protect-pdf
2. Follow the on-page instructions for password protect pdf
3. Your result is generated locally in the browser

## Other pdf tools on PDFFlare

- [Merge PDF](https://pdfflare.com/tools/pdf/merge-pdf): Combine multiple PDFs into one
- [Split PDF](https://pdfflare.com/tools/pdf/split-pdf): Separate into pages or ranges
- [Compress PDF](https://pdfflare.com/tools/pdf/compress-pdf): Reduce file size
- [PDF to Word](https://pdfflare.com/tools/pdf/pdf-to-word): Convert to editable DOCX
- [Word to PDF](https://pdfflare.com/tools/pdf/word-to-pdf): Convert DOCX to PDF
- [Excel to PDF](https://pdfflare.com/tools/pdf/excel-to-pdf): XLSX, XLS, ODS to PDF

## About PDFFlare

PDFFlare is a free collection of online tools for working with PDFs, images, text, JSON, and developer utilities. All tools run client-side in your browser — no signup, no upload to our servers, no rate limits.

For the full site index, see https://pdfflare.com/llms.txt.
For the complete content dump in one file, see https://pdfflare.com/llms-full.txt.