DEV3 Free JSON Formatter and Validator — Source Code (React + Tailwind)

Source code of the DEV3 JSON Formatter and Validator, a JSON formatter and validator that reports errors by line and column, sorts keys, minifies and renders a collapsible tree.

Free download: sign in to any DEV3 account and click Download ZIP. Try it live: https://dev3.tech/tools/json-formatter 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

• Pretty print with 2, 4 or tab indent
• Error location extraction from the parser message
• Key sorting and minify
• Collapsible tree with node counts

Tech stack

React 19, TypeScript, Vite, Tailwind CSS 4.

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.