How to Fill Out a PDF Form and Sign It (Free)
Updated 2026-06-21
To fill out a PDF form, open it in a tool that reads its interactive fields, type into each text box, toggle the checkboxes and radio buttons, then download the completed file. With PDF Form Filler & Signer you can do all of that — plus draw a signature — entirely in your browser, so the document never gets uploaded to a server.
Fill the form fields
Most official PDFs (tax forms, applications, intake sheets) are built as AcroForms — they contain real, clickable fields. Here is the full flow:
- Drop your PDF onto the upload area or click to browse. The tool parses it locally and shows the page count, total fields, and how many are fillable.
- Work down the Form fields panel. Type into text boxes, toggle checkboxes, pick a radio option, or choose from dropdown and list-box values. Any values already saved in the PDF are pre-loaded so you only edit what's wrong.
- When everything looks right, click Download filled PDF. The result is saved as your-file-filled.pdf.
Because it reads standard AcroForm fields, the layout and tab order match the original form exactly — no retyping onto a flattened image.
Add and place your signature
Turn on Add a drawn signature to sign the document. Draw in the white pad with your mouse, trackpad, or finger on a touchscreen, and use Clear to start over if the line wobbles.
Then place it precisely:
- Choose which page the signature goes on.
- Pick Left, Center, or Right near the bottom of that page.
- Drag the width slider to scale the signature up or down.
No form fields at all? The tool automatically switches to signature-only mode, so you can still drop a drawn signature onto any page of a flat PDF and download a signed copy.
Flatten or keep it editable
Before downloading, decide what Flatten should do:
- Flatten on (the default) bakes your answers into the page, producing a fixed, non-editable PDF — ideal for contracts and anything you're submitting.
- Flatten off keeps a live AcroForm so you (or a recipient) can change the values later.
Common pitfalls
- File size: keep PDFs under 50 MB, since the whole document loads into memory.
- Encrypted PDFs can't be opened — remove the password first.
- XFA (LiveCycle) forms only expose their classic AcroForm fields; any XFA-only fields won't appear.
- Push-button and existing signature widgets are shown but left untouched, and read-only fields stay as-is.
Why fill PDFs in your browser
Forms often carry sensitive data — Social Security numbers, salaries, signatures. Most online "PDF filler" sites upload your document to their servers. This tool runs 100% locally using pdf-lib: the PDF is read, filled, signed, and saved on your own device, with nothing transmitted and no signup or watermark.
Ready to complete that form? Open the PDF Form Filler & Signer and fill, sign, and download in a couple of minutes.