Most forms arrive flat: a printed sheet, scanned or exported, with a row of underscores where each answer is meant to go. Pick a field type, drag a box where the answer belongs, and it becomes a real interactive field — the kind a reader lets people type into, tick and choose from, and the kind that keeps what was typed when the file is saved. Text boxes, multi-line boxes, checkboxes, dropdowns with their own list of choices, radio groups and date boxes are all here, with names, tooltips, required flags, default values and font sizes. Detect blank lines finds the runs of underscores in the text and puts a named text field over each one. The printed page is never altered, and the form is built on your device.
Features
Six field types: text, multi-line, checkbox, dropdown, radio option and date
Drag to draw, drag to move, pull a corner to resize, arrow keys to nudge by a point
Detect blank lines covers each run of underscores with a named text field, with one-click undo
Name, tooltip, required flag, default value, maximum length and font size per field
Dropdown choices typed one per line; radio options grouped under a single name
Fields the PDF already has are kept untouched and their names are protected
Clashing names, empty dropdowns and boxes too small to click are caught before you build
Try the finished form in the preview, then download the fillable copy
How to use the Make PDF Fillable
Drop the PDF and pick a field type from the palette
Drag a box where the answer belongs, then set its name and options in the panel
Run Detect blank lines to cover underscore rules automatically
Check the preview, then save the fillable copy
Example
Input
membership-form.pdf — 2 pages, no existing fields
Output
membership-form-fillable.pdf — 11 text fields, 3 checkboxes, 1 dropdown, tab order top to bottom
Blank-line detection found nine of the eleven text boxes by itself.
Common errors & troubleshooting
Detect blank lines found nothing. — It looks for runs of underscores in the text layer. Rules drawn as graphics, and scanned pages, have none — draw those boxes by hand, or run PDF OCR first to give the page text to search.
A field name was rejected. — Two fields cannot share a name unless they are radio options in one group, and a full stop in a name would create a parent field, so it is stripped out. Rename one of the pair.
Accented characters vanished from a default value. — Default values are drawn with a built-in typeface that covers Latin scripts, so anything outside it is left out and counted. What people type later is drawn by their own viewer and is not limited in the same way.
The download does not contain what I typed in the preview. — The preview is a live form, so anything typed there stays in the preview. Download the fillable file and fill it in a reader, or use Fill PDF Form to type values in and keep them.
Frequently asked questions
Will the fields I draw work in Acrobat and in a browser viewer?
Yes. They are ordinary interactive form fields with their own appearance streams, not a picture of a form, so any reader that supports filling in PDFs will show them and save what is typed.
Can I add fillable boxes to a scanned form?
Yes. The fields sit on top of the page, so a scan behaves exactly like a digital one. Only the automatic blank-line detection needs a text layer, so on a scan you draw the boxes yourself.
How do radio buttons know they belong to the same question?
They share the field name — that name is the group — and each option carries its own value. Choosing one then clears the others, so give every option in a group a different value.
Is a date box checked for a real date?
No. It is a text field whose chosen format is shown as a tooltip, with no validation and no script behind it, so somebody can still type anything into it.
What happens to form fields the PDF already had?
They are left exactly as they are, drawn as dashed outlines while you work, and their names are reserved so a new field cannot collide with one of them.
Why did a notice mention XFA form data?
Because the file carried an XFA form, an older Adobe layout that most browsers and many readers cannot display. It is removed so that the fields you drew are the ones people actually see.
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