JSON (JavaScript Object Notation) is the universal language of APIs. Whether you're debugging a response or writing config files, knowing how to format JSON properly saves hours.
Pretty vs Minified JSON
Pretty JSON uses indentation and newlines to make the structure human-readable. Use this during development.
Minified JSON removes all whitespace to reduce file size. Use this in production to save bandwidth.
A 10KB pretty-printed JSON file can often be reduced to 7KB minified — a 30% reduction.
Common JSON Errors
Trailing commas — JSON does not allow trailing commas after the last item in an object or array. This is the #1 source of JSON parse errors.
Single quotes — JSON requires double quotes for strings. Single quotes are invalid.
Unquoted keys — Unlike JavaScript objects, JSON requires all keys to be double-quoted strings.
Comments — JSON does not support comments. Use JSONC (JSON with Comments) if you need them.
Validation Before Use
Always validate JSON from external sources before parsing it. Malformed JSON will throw a runtime error that can crash your application.
Use our free JSON Formatter & Validator to format, validate and minify your JSON instantly.