Form fields stop being editable: what's written becomes part of the document. Free, unlimited, and no file ever gets uploaded to a server.
100% private: everything runs on your computer, your files never leave your device.
Flatten PDF turns the interactive fields of a form into ordinary page content, on your own computer. Whatever has been typed, ticked or chosen stops being an editable field and becomes part of the page, drawn in the same place and looking the same as it did.
The distinction matters because a filled form and a flattened form are not the same document. In a filled form the answers live in a separate layer that a reader can still edit, that some readers refuse to print, and that disappears entirely when the pages are copied into another PDF. Flattening writes those answers into the page itself, where nothing can touch them.
That is why almost every other tool on this site tells you to flatten first. Merge, Split, Rotate and Remove annotations all rebuild the document page by page, and a form layer does not survive that rebuild. Flatten it and the answers stay visible in whatever you do next.
The change is one-way. There is no unflatten, so keep the editable original if you might need to correct an answer later.
The form is read, its values drawn into the pages and the file written back, all inside your browser tab. Nothing is uploaded, and no page or field value is sent anywhere.
Forms are exactly the documents that carry the details worth protecting: names, addresses, national identity numbers, bank details. None of it leaves the machine you are sitting at.
Yes. Flattening one PDF at a time is free and unlimited, with no account and no watermark. Flattening several in a single run requires the 7-Day Pass or Pro.
Not as a form. The answers are page content now, so there are no fields left to click. Keep the editable original if you might need to change something later.
No. The values are drawn where the fields were, in the same place and at the same size. Nothing is converted to an image, so the text stays selectable and sharp.
Because merging, splitting or rotating rebuilds the document page by page, and the form layer is a document-level structure that does not survive that. Flattening first turns the answers into page content, which does survive.
No. The whole operation runs in your browser, on your computer. Neither the document nor the values typed into it reach a server.
It comes out as an empty printed form: the boxes are drawn as they looked, but nothing can be typed into them any more.