What is Protect PDF with Password?
Protect PDF with Password is a free online tool that encrypts a PDF so it cannot be opened without a password. It uses the PDF standard security handler (128-bit RC4), so the protected file opens in every mainstream reader, browser and mobile viewer but genuinely rejects anyone without the password. A single click uploads nothing — the PDF is validated, encrypted and downloaded entirely inside your browser for complete privacy.
Common Use Cases
Confidential Documents
Encrypt invoices, contracts and personal files before emailing or storing them so only intended recipients can open them.
Client Deliverables
Share quote or proposal PDFs with a password, then send the password separately over another channel.
QA Test Fixtures
Generate password-protected PDF fixtures to verify that a product correctly handles encrypted documents.
Regulated Data
Add a basic layer of access control to sensitive reports and records before distributing them.
How to Use This Tool
- Upload a PDF by dragging and dropping it or clicking the upload area (one file, up to 100 MB)
- Enter a password of 4-32 characters and confirm it in the second field
- Optionally set an advanced owner password to control permissions — leave blank to keep it simple
- Click "Protect PDF" and wait for the encryption spinner to finish
- Download the protected file and share the password separately — never send both together
Related Tools
Learn More
- ISO 32000-2 — PDF Specification ISO 32000-2, the official specification of PDF security and encryption.