DEV3 PDF Form Filler and Signer — Source Code (React + Tailwind)

Source code of the DEV3 PDF Form Filler and Signer, a browser PDF form filler and signer: AcroForm fields, text, dates, check marks, drawn or typed signatures, highlights and shapes, exported as a flattened PDF.

Download: buy a licence and the ZIP is waiting in Account → Downloads. Try it live: https://dev3.tech/tools/pdf-filler-signer shows the finished tool running.

What is in the download

• A standalone Vite + React + TypeScript + Tailwind CSS project: src/tool holds the tool, shared pieces sit beside it
• package.json with exact versions plus a lockfile, so npm ci works
• README.md (run, build, embed in Next.js or plain React) and an MIT LICENSE

What the code does

• AcroForm text, checkbox, dropdown and radio fields via pdf-lib
• pdf.js page rendering with a percentage-positioned overlay so items scale cleanly
• Signature pad (draw or type) trimmed to a transparent PNG
• Multiply-blended highlights, rectangles and ellipses

Tech stack

React 19, TypeScript, Vite, Tailwind CSS 4, pdf-lib, pdfjs-dist.

Install and customise

The How to install and How to use tabs list the steps. In short: unzip, npm ci, npm run dev, then copy the tool folder into your own app if you want to embed it.

Good to know

• A browser-only tool: there is no backend or database in the code.
• The signature is an image, not a certificate-based digital signature.
• Standard Helvetica only, so non-Latin text is replaced with question marks.
• Pages rotated inside the PDF are not corrected for.