FileLabsFill PDF Form
Type into AcroForm fields that already exist. No new fields are added.
- 1Upload
- 2Options
- 3Process
- 4Download
Drop a file here, or browse.
PDF only · processed in your browser
Fill PDF Form is for a contract, application, or tax worksheet that already has AcroForm fields — a name box, a yes/no checkbox, a dropdown — when you want those values saved in the PDF. It is a Local tool: one PDF stays on this device. pdf-lib reads only the fields that already exist and writes the values you type. No new fields are created. A file with no AcroForm fields, and an XFA-only form, stops with an error. Appearance text uses Helvetica, so letters outside the Latin set cannot be drawn. This page does not edit body text that is already painted on the page. A visible signature is Sign PDF. The text layer is PDF to Text.
This tool is free to use.
Files stay on this device.
How to fill a PDF form
- Add one PDF. Processing stays on this device — the file is not uploaded.
- Confirm Fill PDF Form is Local — pdf-lib reads the AcroForm in a Web Worker.
- Fill the fields that appear. Checkboxes, dropdowns, and radio groups only offer choices already stored in the file.
- If the page says there are no fillable fields, this PDF cannot be filled here. Do not expect new boxes to appear.
- Process and download the PDF. Sibling jobs are on the PDF hub. To pull an attached spreadsheet instead, use Extract Files from PDF.
Fill PDF form FAQs
Does the file leave this device?
No. This is a Local tool. The PDF stays in the browser and is not uploaded.
Will this add fields that are not in the file?
No. Only AcroForm fields already in the PDF are listed. A scanned form that is just a picture of boxes has nothing to fill.
What if there are no fields?
The job stops with an error. XFA-only forms and PDFs without an AcroForm are not filled. Nothing is downloaded.
Can I type any language?
The appearance is drawn in Helvetica. Latin letters, digits, and basic punctuation work. Other characters stop the job instead of being dropped silently.
How is this different from Sign PDF?
Sign PDF draws a signature image on a page. This page writes values into existing form fields. It does not invent a signature field.
Does this rewrite the paragraph text?
No. Text already painted on the page stays as it was. This is not an editor for body copy. The text layer can be copied with PDF to Text.
What if the PDF asks for a password?
Open it first with Unlock PDF when you already know the password — that stays Local. This page does not guess a forgotten password.
Page guide updated 2026-10-11