MammothPDF
Tools

Fill PDF forms

Fill in a PDF form's fields right on the page, tick its boxes, pick from its lists, then save it - filled in and, if you want, locked so nobody can change it.

Drop PDF files here

Drag them straight from your desktop

or
  • PDF files only
  • Up to 15 MB each
  • 2 files a run - unlimited with Pro

Frequently asked questions

How do I fill a PDF form online?

Open the file and a real input appears on every field - text boxes, check boxes, radio buttons, drop-downs. Type your values and save.

What does "flatten" do?

It burns the values into the page and removes the fields, so the form cannot be edited again and looks identical in every reader. Leave it off to keep the form fillable.

Is my personal data uploaded?

Nothing is uploaded: the file is opened and processed inside your browser and never leaves your device. Close the tab and it is gone. Form values are the most personal data a PDF tool handles, so this is the whole point.

Why does my form show no fields?

Either the PDF has no form fields (it is a printed form scanned to PDF - use the Edit tool to write on it) or it is an XFA form, which only Acrobat renders and this tool refuses rather than produce a file that looks wrong elsewhere.

Missing something, or did the result surprise you?