Fill it in, flatten it, send it — without an upload
Drop a fillable PDF above — a tax form, application, or intake sheet — and its fields appear twice: overlaid on the page preview and in a clean sidebar list. Type, tick, and select your way through, then download the filled copy. Because everything runs on your device, the answers you type into that W-9 or visa application are never uploaded to anyone’s server.
The optional Flatten step bakes your answers into the page itself and strips the interactive fields — the digital equivalent of filling a form in pen instead of pencil. Recipients see exactly what you entered in any viewer, and nothing can be edited afterwards.
If your form needs a signature drawn on it, continue to Sign PDF. Password-locked forms must go through Unlock PDF first. Scanned paper forms have no fields to fill — rebuild simple documents with Text to PDF, stamp them with the PDF watermark, or permanently remove sensitive parts with the PDF redactor.
Frequently asked questions
Is my filled-in form uploaded anywhere?
No. The PDF is parsed, filled, and saved entirely in your browser with pdf-lib. Form PDFs are usually the most sensitive documents there are — tax forms, applications, medical intake — so nothing, not the file and not your answers, ever leaves your device.
Why does it say my PDF has no fillable fields?
Only PDFs with real AcroForm fields — the kind where your PDF reader shows clickable boxes — can be filled programmatically. A scanned paper form or a "flat" PDF is just a picture of a form; there is nothing for software to fill. For those, you would need to add text on top instead, or rebuild the document with our Text to PDF tool.
What does "Flatten" do, and when should I use it?
Flattening bakes your answers permanently into the page content and removes the interactive fields, so the result is read-only — nobody downstream can edit what you entered, and the values display identically in every PDF viewer. Use it when submitting a final version. Leave it off if you (or the recipient) may need to change answers later.
Which field types are supported?
Text fields (including multiline), checkboxes, radio button groups, dropdowns, and multi-select option lists. Signature fields are shown but cannot be signed here — a cryptographic signature is a different beast. For drawing a signature image into a PDF, use our Sign PDF tool.
Why do the on-page input boxes sometimes sit slightly off?
The overlay inputs are positioned from each field’s stored rectangle, and a minority of PDFs store unusual geometry (rotated pages, odd coordinate origins). That is why the sidebar list is the source of truth: every field is always fillable from the sidebar even when its overlay is imperfect.