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How to create a fillable PDF form

Published November 6, 2026 by Jason Nel

A fillable PDF has interactive fields: boxes people can type into, checkboxes they can tick and drop-down lists they can choose from. Many people search for how to make one from a Word document, and the answer depends on which program you have. This guide covers the main routes, how to test the result, and what to do once it is filled in.

Note: ModifyPDF fills in existing forms, adds text to forms that have no fields, and locks filled answers. It does not design new form fields, so you create the fields in a program built for that and use ModifyPDF afterwards.

Option 1: LibreOffice Writer (free)

  1. Write the form in Writer as you would in Word: labels, tables and spacing.
  2. Turn on the form toolbar from View › Toolbars › Form Controls.
  3. Insert text boxes, check boxes, list boxes and drop-downs where answers should go.
  4. Choose File › Export as PDF and tick Create PDF form on the General tab.

LibreOffice then writes the controls into the PDF as real form fields.

Option 2: Adobe Acrobat

Acrobat Pro has a Prepare a form tool that detects likely fields in an existing PDF and lets you add, move and rename them. It is the most capable option for a form you already have as a PDF, but it needs a paid subscription.

Why Save as PDF from Word is not enough

Microsoft Word’s content controls (text boxes, check boxes and drop-downs) work inside Word, but when you save or export to PDF they are drawn as plain page content, not as fillable fields. If your goal is a fillable PDF, export from a program that writes real PDF fields, such as LibreOffice Writer or Acrobat.

Test the form before you share it

  • Open it in Fill PDF form. If your fields are highlighted and you can type into them, the form works in a browser.
  • Tab through the fields to check the order makes sense.
  • Try it on a phone too, since some mobile viewers ignore fields.

No fields? Fill a flat PDF anyway

If you only have a flat PDF or a scan, you do not have to build fields at all. Edit PDF lets you place text, ticks and a signature exactly where they belong. This is often quicker for a one-off form.

Lock the answers when it is filled in

A filled form can still be edited by whoever receives it. Flatten PDF draws the answers into the page and removes the interactive fields, so what you sent is what they see. Check every page afterwards, and keep an unflattened copy if you may need to change something.

Frequently asked questions

Can I make a fillable PDF from Word for free?

Yes, with LibreOffice Writer. Open your Word file in it, add form controls and export with “Create PDF form” ticked.

Can I fill in a PDF that is not fillable?

Yes. Use Edit PDF to add text over the page. The result looks the same on screen and in print.

Does the form data stay private?

Filling, editing and flattening in ModifyPDF all happen in your browser. The PDF is not uploaded.