Stop Switching Tabs — One Free Tool Replaces All Your JSON & Dev Tools

Every day I was doing the same thing: Paste API response into some random formatter Open another tab to decode the JWT Open another tab for Base64 Open another tab to test a regex Four tabs. Same tools. Every single day. So I built JsonMaster — a free developer toolbox that puts 12 tools in one tab. 👉 https://jsonmaster.netlify.app/ No login. No ads. Your data never leaves your browser. What's Inside JSON Formatter & Validator Paste raw minified JSON and instantly see it beautified. Built on Monaco Editor — the same engine as VS Code — so you get syntax highlighting, inline error squiggles, code folding, and keyboard shortcuts you already know. JSON Converters Convert JSON to: YAML — for Kubernetes, Docker Compose, GitHub Actions CSV — for Excel, Google Sheets, data pipelines XML — for legacy systems and SOAP APIs TypeScript Interface — paste an API response, get a typed interface instantly Zod Schema — instant runtime validation schema for TypeScript projects .env file — flatten neste