Encrypt PDF - Add Password Online

---

title: "PDF Encrypt" description: "Add password protection to PDF files" tool: pdf-encrypt

PDF Encrypt Tool - Protect Your Documents with Password

PDF encryption protects sensitive documents from unauthorized access. This tool adds password protection to your PDFs directly in your browser, no uploads, no servers, complete privacy.

What is PDF encryption?

PDF encryption scrambles a document's contents so they're unreadable without a password. When someone tries to open an encrypted PDF, they need the password to view the content.

People encrypt PDFs for different reasons:

1. Business confidentiality: Contracts, financial reports, strategic plans
2. Personal information: Tax returns, medical records, legal documents
3. Intellectual property: Research papers, designs, proprietary content
4. Compliance: HIPAA, GDPR, and other regulations that require data protection

How to use this tool

1. Upload your PDF: Click or drag to select the file
2. Enter a password: At least 4 characters
3. Confirm the password: Type it again to confirm
4. Click Encrypt: Processing happens instantly in your browser
5. Download the encrypted PDF: The result file requires the password to open

PDF encryption standards

This tool uses RC4 128-bit encryption, which is widely supported by all modern PDF readers including Chrome, Firefox, Adobe Acrobat, and macOS Preview.

• 128-bit RC4: Provides solid protection for most use cases
• Universal compatibility: Works with all major PDF readers
• No server uploads: Everything processes locally in your browser

Privacy guarantee

All processing happens locally in your browser. Your files never leave your device. No copies stored on servers. Once the page closes, all data is gone.

Best practices for PDF passwords

1. Use strong passwords: Mix uppercase, lowercase, numbers, and symbols. At least 8 characters.
2. Avoid the obvious: "password" and "123456" are still common. Don't use these.
3. Don't reuse passwords: Different passwords for different documents.
4. Send PDFs and passwords separately: Don't email both together.

Removing passwords from PDFs

If you have an encrypted PDF and know the password, use our PDF Decrypt tool to remove the protection.

Compatibility

The encrypted PDF can be opened in:

• Google Chrome
• Mozilla Firefox
• Adobe Acrobat Reader
• macOS Preview
• Windows Edge
• Most other PDF readers