Is my file uploaded to a server?

No. This tool runs entirely in your browser via WebAssembly — your file never leaves your device. You can verify this in your browser's DevTools Network tab.

What does flattening do?

It bakes interactive form fields (and their values) into the page as static content, so they display identically everywhere and can no longer be edited.

What if my PDF has no form?

Then there's nothing to flatten — the file is saved unchanged. It's safe to run either way.

Flatten PDF

Bake form fields and annotations into the page so they can't be edited.

Local processing — your files never leave your browser