Protect PDF
Add a real document-open password with AES-256 encryption.
Processed on your device · No sign-upDrop your PDF here
or choose a file from your device
40 MB per file · 80 MB total · processed on your deviceQUICK START
How to use Protect PDF
- Choose an unencrypted PDF.
- Enter and confirm a strong password.
- Download and keep your password somewhere safe.
GOOD TO KNOW
A few useful details
Encryption runs locally using qpdf WebAssembly. Lost passwords cannot be recovered here. Use a modern PDF reader.
Editing a digitally signed PDF can invalidate its signature. Keep the signed original.
Common questions
Are my files uploaded?
No. Processing happens in your browser. The site downloads its own code, fonts, and processing engines; it does not send your files or passwords to a processing service. Reset or close this tab to release files from the app.
What are the limits?
Up to 40 MB per file, 80 MB in total, and 30 input files per job. PDFs are limited to 200 pages and images to 24 megapixels. Available device memory can impose lower practical limits. Try smaller batches on a phone.
Will my original file change?
No. Each tool creates a new output for you to download. Review the preview and downloaded result before relying on it, especially for important or signed documents.