A browser-based PDF form filler that reads the interactive fields inside a PDF, lets you type into them, and exports a completed file — optionally flattened so the values are locked in. It is built for anyone who routinely deals with fillable PDFs: tax and benefit forms, HR onboarding packs, rental and mortgage applications, consent and intake forms, expense claims, and the endless official documents that ship as AcroForm PDFs. Instead of printing, hand-writing and re-scanning, you fill the form digitally in a few seconds and download a clean, professional result.
How it works
When you load a PDF, the tool parses its AcroForm — the layer that defines
interactive form fields — using the pdf-lib library running entirely in your
browser. Each field is detected by type: plain text boxes, checkboxes,
radio groups, dropdowns and multi-choice option lists. For anything
with a fixed set of choices, the allowed options are read directly from the PDF,
so you can only select values the form actually accepts. Existing default values
are pre-loaded so you see the form in its current state.
As you edit, every change updates an in-memory copy of the field values; the
original PDF bytes are kept untouched so you can export repeatedly. When you
click Fill + download PDF, the tool writes your values back into the form,
refreshes each field’s visual appearance so viewers render the text reliably,
and — if flatten is enabled — calls flatten() to merge the values into the page
content and strip out the editable layer. The finished file is handed to your
browser as a download. Nothing ever leaves your device, which matters when the
form contains a national insurance number, salary, or medical detail.
Example
Suppose you receive a rental application PDF with text fields for name, address
and monthly income, a checkbox for references available, and a dropdown for
tenancy length. Load the file and the tool lists all five fields with readable
labels. Type your details, tick the checkbox, choose 12 months from the
dropdown, leave flatten on, and download. The result is a finished
rental-application-filled-flat.pdf where every value is permanently set and the
landlord cannot accidentally edit it. Need an editable copy instead — say, a
template you will adjust per applicant? Turn flatten off and the fields stay live
for the next person.
| Field type | What you do | Exported result |
|---|---|---|
| Text | Type a value | Text printed in the field |
| Checkbox | Tick or untick | Box shown checked / blank |
| Radio group | Pick one option | Matching button selected |
| Dropdown | Choose from list | Selected value shown |
Every figure and field is processed in your browser — your PDF is never uploaded.