Encrypt PDF

Password Protect PDF Files Free Online

Adding a password to a PDF file prevents unauthorized access. Only people who know the password can open the document. This is important for any file that contains personal, financial, legal, or business information. This free PDF encryption tool lets you protect your PDF with a password instantly, without uploading it to any server.

PDF encryption works by scrambling the file content with a cipher. The password acts as a key to decrypt the file when it is opened in a PDF reader. Without the correct password, the file content cannot be read.

This tool adds user password protection using PDF-lib in your browser. No file or password data leaves your device at any point in the process.

How PDF Password Protection Works

PDF files support two levels of password protection. A user password (also called an open password) is required to open and view the file. An owner password controls permissions such as printing, copying, and editing.

This tool sets a user password that prevents the file from being opened without the correct password. PDF readers such as Adobe Acrobat, Foxit, and browser-based viewers all support this standard. When someone tries to open the protected PDF, they see a password prompt.

The encryption standard used is part of the PDF specification and is widely supported. Encrypted PDFs are compatible with all major PDF readers on Windows, Mac, iOS, and Android.

How to Encrypt a PDF

Step 1 – Upload your PDF. Click or drag your PDF file onto the upload area.

Step 2 – Enter a password. Type a strong password. A good password is at least 8 characters and includes numbers, letters, and symbols.

Step 3 – Confirm the password. Enter the password again to confirm there are no typos.

Step 4 – Encrypt. Click the Encrypt button. The tool processes the file and adds password protection.

Step 5 – Download and save your password. Download the encrypted PDF and store your password in a secure place. You will need it every time you open the file.

Why Password Protect a PDF

Sensitive personal data. Medical records, tax returns, ID scans, and financial statements are all examples of documents that should not be accessible to anyone who finds or receives the file.

Business confidentiality. Contracts, pricing documents, business plans, and employee records require access control when shared digitally.

Legal compliance. Data protection regulations in many countries require that personal information be secured in transit and at rest. Encrypting PDFs helps meet this requirement.

Email security. Emails can be intercepted. A password-protected PDF ensures the content is unreadable even if the email is accessed by the wrong person.

Client deliverables. Agencies and consultants often send encrypted reports so only the intended client can view them.

Limitations

Not a substitute for strong security. PDF password protection deters casual access but is not as strong as enterprise-level document security systems.

Password recovery is not possible. If you lose the password, the file is effectively locked. Keep a backup of the unencrypted version.

No permission controls. This tool adds an open password only. Controlling printing, copying, or editing requires an owner password, which this tool does not set separately.

Related Tools

• Watermark PDF – Add a visible watermark in addition to password protection.
• Merge PDF – Combine documents before encrypting them.
• Compress PDF – Reduce file size before adding a password.

Frequently Asked Questions