Format, minify and validate JSON instantly. Indentation is selectable, syntax errors are reported clearly, and the whole tool runs in your browser — your JSON is never uploaded. 100% Local
How to Use the JSON Formatter
Paste or type JSON into the left pane, pick an indentation width, then press Format. Use Minify to strip all formatting. If the JSON is malformed, the status line says so instead of showing a broken result.
What it checks
Valid JSON per the JSON grammar: keys, commas, brackets and quotes.
Object and array key totals as a quick sanity check.
Both pretty printing and single-line minification.
Features
Pretty print with 2 or 4 space indentation
One-click minify to a single line
Clear, immediate validation feedback for invalid JSON
All processing runs locally in your browser. Your JSON is not uploaded to any server.
Formatting output is a tool result — review it before using it in production.