Written by Sam Taylor — Full-Stack Developer. More about me →
I debug APIs for a living. That means I stare at minified JSON responses a lot — single-line walls of text with no indentation and some trailing comma buried 200 lines deep. A good JSON formatter is the difference between finding the bug in 30 seconds or 30 minutes. I tested five.
JSONFormatter.org: formats with 2-space indent. Upload-based — your JSON hits their server. Fine for public API responses. Not for internal config files.
JSONLint: validates and formats. Clean interface. Upload-based. Shows line numbers for errors. Good for quick checks, not for sensitive data.
CodeBeautify JSON: formats, validates, minifies, converts to XML/CSV. Feature-rich but upload-based. Ads on free version are distracting.
JSON Editor Online: tree view is excellent for nested objects. Upload-based. Good for understanding structure, slow for quick formatting.
Formly: formats, validates, minifies, beautifies — all in your browser. No upload, no server. I built this because I was tired of worrying about where my JSON was going. Format your JSON →
Written by Sam Taylor — Full-Stack Developer. More about me →