About the Fill PDF Form
Fill PDF Form finds the real form fields inside a PDF and shows them as a simple list you can fill in: text boxes, checkboxes, dropdown menus and radio buttons. When you press Fill and download, your answers are written into the PDF. You can leave the form editable so it can be changed later, or flatten it so the answers become a permanent part of the page. Only real fillable fields work. A page that merely looks like a form has no fields to fill, and the tool tells you so. Signature and button fields are skipped, and letters outside the standard Latin set are replaced with a question mark. The PDF stays in your browser.
Updated September 2026
How to use the Fill PDF Form
- 1Select a fillable PDF form.
- 2Wait for the list of fields to appear and read the count.
- 3Type your answers, tick the boxes and choose from the menus.
- 4Tick Make the answers permanent if you want to lock the answers in.
- 5Press Fill and download and save the finished PDF.
Fillable forms and flat forms
A fillable form contains named fields that a PDF program can edit: text boxes, checkboxes, menus and radio buttons. Government forms, school applications and many company forms are made this way, and this tool lists every one of them.
A flat form is just a picture of a form, with no fields. Scans of paper forms are flat. If you see the message that no fields were found, the file is flat, and typing on top of the page with Edit PDF is the way to fill it.
Keep it editable or make it permanent
With flatten off, the fields stay live: you can open the saved file, in any PDF program, and change an answer. That suits a draft, or a form you plan to send back and forth.
With flatten on, every answer is printed onto the page and the fields are removed. Choose it for the final copy that you email or upload to an office, since nobody can then change the values by accident. Keep the unflattened file too in case you need to correct something.
Checkboxes, dropdowns and radio buttons
- Text fields: type the answer; a field with a length limit cuts extra characters.
- Multi-line boxes: press Enter for a new line; long answers may not fit the visible box.
- Checkboxes: tick the box to check it and untick it to clear it.
- Dropdowns and lists: choose one option, or none to clear the field.
- Radio buttons: pick one choice in the group; the others turn off.
Fill on your phone
Fields are shown as a plain list with large inputs, so you can complete a form with your thumbs instead of zooming into tiny boxes. Long field names are shortened on screen, and the full name appears as a tooltip on computers.
Some PDF viewers redraw fields in their own style, so the look of a filled field can differ between programs even though the answer is the same. Open the finished file once to check it, and use Merge PDF to join it with any attachments you must send along.
Features
- Text fields, multi-line boxes, checkboxes, dropdowns and radio buttons
- Fields listed in the order they appear in the PDF
- Keep the form editable or flatten it
- Cuts answers to a field's own length limit
- Clear message when a PDF has no fields
- Works on phones and computers
- No upload, no account
Frequently asked questions
Why does my PDF have no fields?
Many PDFs only look like forms: the boxes are lines drawn on the page, not fields. Such a file is a flat form, and this tool finds nothing to fill. Use Edit PDF to place text on top of the page instead.
What does flatten mean?
Flattening turns the answers into ordinary page content and removes the fields. The text can no longer be edited by the next person, which is useful before you send a form that must not change. Leave it off if you may need to correct an answer later.
Can I fill a PDF on iPhone?
Yes. Open the page in Safari, choose the PDF from Files, fill in the list of fields and save the result to Files or share it. The list uses large touch targets, so it is easier than pinching to zoom into small boxes.
Can I sign it too?
Signature fields are not filled by this tool. Fill the form here first, then add your signature with Sign PDF, which places a drawn or typed signature on the page.
Is my filled form uploaded?
No. The form is read and filled by your own browser, so tax forms, applications and medical papers are not sent to a server. Nothing is stored once you close the tab.
Why do some letters change?
The answers are written with the form's standard font, which covers Latin letters and common accents. Letters from other scripts have no shape in that font, so they become a question mark, and the page warns you as you type them.
What if my form says it uses XFA?
XFA is an old dynamic form format that only Adobe Reader can fill properly. This tool cannot fill it and says so. Open the form in Adobe Reader, or print it and use Edit PDF to type on the page.