Protect PDF with a Password

Password-protect your PDF — 100% in your browser

Add real password encryption to any PDF with GroPDF. Unlike other tools, your file never leaves your device — the entire encryption happens locally in your browser using industry-standard PDF password protection.

How to protect a PDF

1. Drop your PDF onto the page. It stays on your device.
2. Set a password (minimum 4 characters) and confirm it.
3. Click Encrypt — your browser encrypts the PDF locally.
4. Download your password-protected PDF.

Privacy by design

🔒 100% Private — Your PDF is processed entirely in your browser. Your file and password are never uploaded to our server. There is no server processing, no cloud, no tracking of your document.

Compatibility

The protected PDF uses standard 128-bit PDF encryption, so it opens in Adobe Acrobat, Chrome, Edge, Preview on Mac, and every major PDF reader — they'll all ask for your password.

Steps at a glance

1. Upload the PDF you want to protect.
2. Enter a strong password (and confirm it).
3. Click Protect — your file is encrypted on GroPDF's secure server.
4. Download the protected PDF. The original is deleted from the server immediately.

Why protect PDFs with GroPDF?

PDF encryption is one of the few things browsers can't do well alone, which is why Protect PDF runs on GroPDF's server using standard PDF encryption. The tradeoff is honest and narrow: your file is transmitted, encrypted, and then deleted immediately — it's never stored, indexed, or kept. For everything else on GroPDF, processing stays in your browser; this is the one tool that genuinely needs a server, and it's upfront about it.

Common use cases

• Password-protecting a contract before emailing it.
• Securing HR documents containing salary or personal data.
• Locking a financial report shared with a small group.
• Adding a password to personal scans (IDs, certificates) before cloud backup.

Things to know

PDF passwords deter casual access but aren't unbreakable — use a long, unique password. This tool encrypts 100% in your browser; your file never leaves your device.