Protect PDF
Add password protection to your PDF
At a glance
- Use this page to protect files quickly with a guided workflow.
- Accepted input: .pdf.
- Output: downloadable file generated in-browser for supported workflows.
- Upload Choose your file
- Process Runs locally
- Download Save result
Drop your file here
or tap to browse · accepts .pdf
Runs in your browser. No file uploads for supported tools.
Best on desktop for 100MB+ files · mobile recommended under ~100MB.
How local processing works
- Your PDF is processed in your browser using local JavaScript libraries.
- PDFWhisk does not upload your file to a processing server for supported tools.
- Only normal page assets load from the site (HTML/CSS/JS), not your document contents.
Selected files
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Support: hello@pdfwhisk.com (reply in ~24h)
Security & privacy detailsHow this tool helps
Secure your PDF documents with password protection. Set a password that must be entered to open and view the document. Perfect for protecting sensitive contracts, financial documents, personal records, or any file you want to keep confidential when sharing via email or cloud storage. Choose your encryption strength for the right balance of security and compatibility. The password-protected PDF can be opened in any standard PDF reader that supports encryption. Since our tool processes everything in your browser, your original unprotected document and your chosen password never leave your device. Use it when you need to unlock pdf, watermark pdf, compress pdf.
Best for
How it works
PDFWhisk uses PDF-lib's encryption capabilities to apply password protection to your PDF. The document is encrypted with your chosen password using industry-standard algorithms. Only someone with the correct password can open and view the file.
Frequently asked questions
How secure is the encryption?
PDFs are encrypted using AES-256, the same encryption standard used by banks and governments. Without the password, the document cannot be opened.
Can I set different passwords for viewing and editing?
The free version sets an open password (required to view). Pro users can set separate owner passwords to control printing, copying, and editing permissions.
What if I forget the password?
There is no way to recover a forgotten password. We never see or store your password. Keep it in a safe place.
Will the protected PDF work in all readers?
Yes. Password-protected PDFs are supported by Adobe Reader, Preview (Mac), Chrome, Firefox, and all major PDF readers.
Is my password sent to your server?
No. The password is used only in your browser to encrypt the file. It never leaves your device and we have no way to access it.
What to do next
Chain tools together for a complete workflow.