How to Fill Out a PDF Form Online (Free)

To fill in a PDF form, open Fill PDF Form and add the PDF. Every field in the form — text boxes, checkboxes, radio buttons and drop-down lists — is listed so you can type your answers and pick options, then download the completed PDF. Your answers are filled in on your device, which matters for forms full of personal details.

How to fill out a PDF form

1. Open Fill PDF Form and add the PDF. The tool shows how many fields it found.
2. Fill in each field: type into the text boxes, tick checkboxes, choose radio buttons and pick from the lists. Read-only fields are shown but can't be changed.
3. Decide whether to Flatten the answers (see below).
4. Click Download filled PDF.

The filled PDF opens in any app — Adobe Reader, Edge, Chrome, Preview, or the Files app on a phone — with your answers in place.

Fillable or not? Check first

A "fillable" PDF has built-in form fields. Many official forms do: tax forms, visa and passport applications, insurance claims, school and club registrations. Others are just printed pages saved as PDF, with lines you're supposed to write on.

The tool tells you straight away. If it says this PDF has no fillable fields, use Add Text to PDF instead — click anywhere on the page and type. See how to type on a PDF for that method.

Should you flatten the form?

Ticking Flatten turns your answers into ordinary page content. The form looks the same, but the fields disappear, so nobody — including you — can change the answers afterwards.

• Flatten the final copy you submit, especially when sending it to someone you don't know, or when a portal shows empty fields (some upload systems ignore form fields but always display flattened text).
• Don't flatten a copy you might still need to edit, or a form the recipient expects to process automatically from its fields — some organisations read the field values directly.

Not sure? Download both: an editable copy to keep, and a flattened copy to send. You can also flatten later with Flatten PDF.

Signing the form

After filling it in, add your signature with Sign PDF: draw, type or upload it and place it on the signature line. Fill first and sign last, so the signature sits on the finished document.

Why forms go wrong in browsers

If you've ever filled a form in your browser's built-in PDF viewer and found the answers missing when the recipient opened it, you've met the most common PDF form problem: the viewer didn't save the field values properly, or you printed to PDF and lost them. A tool that writes the values into the PDF's fields and offers flattening avoids both.

Limitations to know about

• Languages: the standard PDF fonts cover English and Western European languages. Characters from other alphabets — Chinese, Arabic, Cyrillic and so on — can't be typed into the fields here.
• Calculated fields: some forms add up totals with built-in scripts. Those scripts don't run here, so type totals yourself if a field doesn't fill automatically.
• Signature fields: certificate-based signature fields can't be signed here; Sign PDF places a visible signature image instead.
• Locked forms: a password-protected form must be unlocked with Unlock PDF first.

Frequently asked questions

Are my answers uploaded?

No. The form is filled in your browser, so your name, address, ID numbers and income stay on your device.

Can I fill a PDF form on my phone?

Yes. On a small screen the field list is easier to use than tapping tiny boxes on the page. The completed PDF goes to your Downloads folder.

Can I save and continue later?

Download the filled PDF without flattening. Later, open that file in the tool again — your earlier answers are still in the fields.