Set an open password so only authorized people can view the document, and optionally set a separate owner password to restrict printing and editing. The encryption happens locally — your password is never transmitted anywhere.
Or drop it here to start immediately
This tool processes your files directly in your browser — nothing gets uploaded to a server. When you're working with lock your pdf with a password, the document stays on your machine from start to finish.
Select the PDF file you wish to encrypt and protect.
Enter a strong password and customize printing or copying permissions.
Apply local encryption and download your secured PDF.
Everything you need to know about lock your pdf with a password.
Upload PDF: Select the PDF file you wish to encrypt and protect. Define Key: Enter a strong password and customize printing or copying permissions. Secure File: Apply local encryption and download your secured PDF. All of this is done on your machine.
Absolutely. Because NexPDF runs entirely client-side using WebAssembly, the document is never uploaded to any external server. Your sensitive data is kept 100% private.
No, there are no artificial file size caps. The only physical limit is your device's available browser memory, which easily handles large documents.
Yes, NexPDF is cached inside your browser after the first load. You can disconnect your internet and continue to use the tool completely offline.
Drop your file in the workspace at the top of the page. No registration required.
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