How the json formatter works
JSON Formatter is a developer utility that parses, indents, and validates raw JavaScript Object Notation (JSON) strings according to RFC 8259 specifications. Messy, unescaped, or minified single-line API responses are transformed into clean, readable, nested structures with customizable 2-space or 4-space indentation.
If your JSON contains syntax mistakes (such as missing commas, unquoted keys, or trailing commas), the validator pinpoints the exact line and position of the error so you can debug immediately.
Step-by-step instructions
- Paste your raw JSON string into the input panel.
- Click Format / Beautify to indent with clean spacing, or Minify to strip all whitespace.
- Use Copy to clipboard to grab the validated output.
RFC 8259 Parsing & Serialization
JSON.stringify(JSON.parse(input), null, indentSpaces)Input is parsed using the native ECMAScript JSON engine. Syntax errors throw structured parse exceptions identifying token positions. Formatted output is serialized with deterministic indent formatting.
Practical example
Input: {"status":"ok","code":200,"items":["a","b"]} Formatted: { "status": "ok", "code": 200, "items": [ "a", "b" ] }
Frequently asked questions
Is my proprietary JSON payload safe to paste here?
Yes, absolutely. Parsing and formatting take place 100% in your local browser runtime. Your data never touches any server or API endpoint.
Can this tool fix invalid JSON automatically?
The tool highlights the exact character error location and reason so you can correct syntax errors like unquoted keys or trailing commas.
Does it support minification for production APIs?
Yes! Click the Minify option to strip all unnecessary whitespaces and line breaks to minimize payload size.