PDF & Files
Fill a PDF Form Online
Free to useNo sign-up requiredNo watermarkRuns in your browser
Many PDFs - application forms, tax forms, intake sheets - are built with real, interactive fields: text boxes, checkboxes, radio buttons and dropdowns baked into the file itself. This reads those fields directly and gives you one input for each, matched to its actual type, so filling it in is typing into boxes rather than trying to click precisely on a flat image of a form.
This only works on a PDF that actually has fillable fields (an "AcroForm"). If a form was scanned or flattened into a plain image with no real fields, there is nothing here to fill in - see the FAQ below for what to do with that kind instead.
How this tool works
Choose the PDF form
Its real fields are read and one input is shown for each.
Fill it in
Text boxes, checkboxes, radio buttons and dropdowns, exactly as the form defines them.
Flatten it, if you want to
Optional - turns the filled answers into permanent page content that displays identically everywhere.
Download
Get the completed PDF.
How it works
A fillable PDF stores its form as an "AcroForm": a list of named fields, each with a type (text, checkbox, radio group, dropdown and a few rarer ones) and a position on the page. This reads that list directly with pdf-lib, the same library every PDF-editing tool on this site is built on, and renders a matching input for each field it recognises.
Typing into a box, checking a checkbox or picking an option writes the value straight back into the field inside the PDF - not into a separate layer on top of it - so the result opens correctly in any PDF reader, not only this one.
Flattening is optional and happens last. It converts every filled field into plain, non-editable page content, which is worth doing when the completed form needs to look identical in every viewer it might be opened in - some PDF readers render interactive form fields slightly differently from each other, and flattening removes that variation entirely.
What this needs to work
The PDF has to be a genuine fillable form - one built with real AcroForm fields, which most application forms, government forms and templates from form-building software are. If a form is a scan or a flat image, it has no fields to detect, and this tool says so rather than guessing at positions on the page.
- Works: text fields, checkboxes, radio button groups and dropdowns.
- Read-only here: signature fields, list boxes and buttons - present but not editable in this version.
- Does not work: a scanned or flattened form with no real fields at all.
A scanned form has no fields to fill
If this tool reports no fillable fields, the form is almost certainly a picture rather than a real interactive PDF - common with forms that were printed, filled by hand, then scanned back in. There is no reliable way to detect "blank" positions on a flat image, so filling that kind of form means printing it, or using a different kind of tool built for annotating over an image rather than filling real fields.
Worked examples
A job application form
Type directly into each labelled field instead of trying to align text over a flat image.
A government or tax form with checkboxes
Checkboxes and dropdowns behave like real form controls, not clicks on a picture.
A form you need to send back looking consistent
Flatten it before sending, so it displays identically in whatever PDF reader the recipient uses.
Frequently asked questions
Is this PDF form filler free?
Yes - free, no sign-up, no watermark and no limit on how many forms you fill in.
Are my files uploaded to a server?
No. Your files never leave your device. The file is opened and processed by your browser on your own machine, so nothing is transmitted to VSThiran and no copy of your document is ever stored on a server.
It says this PDF has no fillable fields - what do I do?
The form is likely a scan or a flattened image rather than a real interactive PDF. There is no reliable way to detect where to type on a flat image; you would need to print it and fill it by hand, or use annotation software built specifically for marking up images.
Should I flatten the form before sending it?
Flatten it if you want the filled answers to display identically no matter which PDF reader opens it - some readers render interactive fields slightly differently. Leave it un-flattened if the recipient might need to edit the answers further.
Does this support signature fields?
Not for filling - a digital-signature field is shown as present but is not editable here. Use Sign PDF to place a drawn or typed signature image on the page instead.
Can I fill a form that has required fields?
Yes - required fields are marked with an asterisk, but nothing stops you from downloading the PDF before filling every one; that is enforced by whatever system the form is submitted to, not by this tool.