Working with JSON every day, I found myself constantly switching between browser tabs to format messy payloads from APIs. Every tool I used either had ads everywhere, required signup, or sent my data to a server. So I built my own. jsonproject.com — a free, browser-only JSON formatter, validator, and auto-fixer. No ads, no signup, no data ever leaves your machine. What it does Format & pretty-print — 2, 3, 4 spaces, tabs, or compact mode Validate against RFC 8259 with inline error markers Minify for production payloads Auto-fix broken JSON — trailing commas, single quotes, unquoted keys Fetch JSON from a URL — paste an API endpoint and format the response instantly Drag-and-drop file upload Format history — last 20 operations saved in session Dark mode Monaco Editor — same editor as VS Code, with full syntax highlighting Tech stack Angular 21 with SSR and prerendering Monaco Editor via ngx-monaco-editor-v2 Tailwind CSS for styling TypeScript throughout The interesting parts Monaco Editor in Angular SSR…