DEVELOPER TOOLS
JSON Formatter & Validator
Make JSON readable. Find syntax errors. Keep your data on your device.
How to format or validate JSON
Paste an API response, configuration or JSON document into Input. Choose Format JSON to add indentation, Validate to check syntax, or Minify to remove unnecessary whitespace. Copy the output or download it as a .json file.
What counts as valid JSON?
JSON uses double-quoted keys and strings. Values can be objects, arrays, strings, numbers, booleans or null. Comments, trailing commas, single-quoted strings, undefined and JavaScript functions are not valid JSON. A single primitive value is also a valid JSON document.
Original numbers stay intact
This formatter changes whitespace rather than converting values back from JavaScript objects. Large integer literals, decimal notation, key order and duplicate keys are preserved. Validation checks syntax; it does not validate an application schema or reject duplicate keys.
Common questions
Is my JSON sent to a server?
No. Formatting and validation run in your browser. Input and output contents are not saved or sent to Analytics.
Can I format an Objective-C dictionary log?
Not directly. Logs using equals signs and semicolons are not JSON. Convert them to JSON with quoted keys and colon separators first.
Does minifying change values?
No. It removes whitespace outside strings while keeping the original tokens, including number notation and escaped text.
How large can a document be?
This tool accepts up to 2 million characters per document. Larger documents are rejected to keep the browser responsive.
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Something not working?
Report the tool, your browser and what happened. Do not include passwords, codes or private files.
Report a problem