Protect PDF
Flatten and lock your PDF — bakes form fields and annotations into the document so they can't be edited. Processed entirely in your browser.
Files stay on your device
100% Browser-based
No account needed
Drop your PDF to protect
Supported: .pdf (up to 100.0 MB)
Frequently Asked Questions
What does 'Protect PDF' do?
It flattens all form fields into the document content, making them non-editable. This prevents others from modifying filled forms or annotations. For true AES-256 encryption, check back soon — we're adding it in our next update.
When should I use this?
Use this after filling out a PDF form to lock your answers, or before sharing a document you don't want others to annotate or modify.
Is it safe to use?
Yes. All processing happens in your browser — your PDF never leaves your device. No upload, no account needed.