Protect PDF File
Encrypt your PDF document with a password to restrict access. All processing occurs locally.
How to use this tool
Step 1: Upload PDF
Select the PDF file you want to secure.
Step 2: Set Password
Enter a strong password to lock the document.
Step 3: Encrypt Document
Click protect to secure your document immediately.
Step 4: Download
Save the encrypted password-protected PDF to your device.
Frequently Asked Questions
How does the PDF password protection work?
The password is used to encrypt the document contents directly in your browser. Without the correct password, PDF viewers cannot open it.
Is my password sent to Zaeyon servers?
No. The entire password generation and encryption process is done locally in your browser memory. We never see your password.
Are my PDF files uploaded to any server?
No. Your PDF files are processed entirely in your web browser using WebAssembly. Your files never leave your device.
Is there a limit on the file size or page count?
No. Since the processing runs locally on your computer, there are no hard limits enforced by our server. It only depends on your system's memory (RAM).
Is this PDF tool completely free?
Yes, all PDF tools on Zaeyon are 100% free with no limits, no registration, and no ads or watermarks.
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Why Zaeyon?
Private, free, and browser-based — no account, no uploads, no compromises.
Zero Uploads
Your files never leave your device. All processing happens locally in your browser memory — nothing is sent to any server.
100% Free Forever
No subscriptions, no hidden fees, no daily limits. Every tool on Zaeyon is permanently free to use without an account.
Instant & Powerful
Powered by WebAssembly — the same low-level technology used in native apps — so processing is fast even for large files.
Works Offline
Once the page loads, the WebAssembly engine runs entirely on your device. No internet connection needed to process files.
Works Everywhere
No software installation required. Runs directly in your browser on Windows, Mac, Linux, iOS, and Android.