JSON Formatter
Format, validate, and minify JSON. Detect syntax errors with line indication.
Reference
JSON Formatting
JSON formatting (pretty-printing) adds indentation and line breaks to make compact JSON human-readable. A well-formatted JSON document reveals its structure at a glance — nested objects, arrays, and scalar values are immediately distinguishable. Formatting is purely cosmetic: it does not change the data; any valid JSON parser produces identical results from formatted or minified input.
Validation
JSON has strict syntax rules: keys must be double-quoted strings, trailing commas are forbidden, and only six value types are allowed (object, array, string, number, boolean, null). This tool uses the browser's native JSON.parse() to validate — if the input is not valid JSON, the error message from the JS engine is displayed so you can pinpoint the problem.
Minification
Minifying JSON removes all insignificant whitespace (spaces, tabs, newlines) to produce the smallest possible representation. This is useful when transmitting JSON over a network (API responses, config files) to save bandwidth. The savings are displayed after minification so you can see the size reduction.
Privacy
All processing runs 100% in your browser. No data is sent to a server.