JSON Formatter & Validator
Beautify, minify, and validate JSON with one click
Keys: —
Size: —
—
Input
Output
— output will appear here —
About JSON
JSON (JavaScript Object Notation) is the most common data interchange format on the web. Formatted/beautified JSON is easy to read and debug; minified JSON reduces payload size for APIs and storage. This tool validates syntax and reports key counts.
Common issues: trailing commas (invalid in JSON), single quotes instead of double quotes, unquoted keys, and comments (not supported in JSON). Use this formatter to quickly spot syntax errors before deploying your API or config.
lightbulb Example
Input:
{"a":1,"b":[2,3]}1Formatted with 2-space indent
2Key count: 2 (top-level)
✓ Valid JSON — ready to use
quizFrequently Asked Questions
What is the difference between formatted and minified JSON?
Formatted JSON uses indentation and newlines to make the structure human-readable. Minified JSON strips all whitespace, producing the smallest possible string for transmission. A 10 KB formatted JSON might become 6 KB minified. Use formatted JSON for debugging and development; use minified for API responses and storage where bandwidth matters.
Why does my JSON fail to parse?
Common causes: trailing comma (JSON does not allow commas after the last item), single quotes (JSON requires double quotes for strings), unescaped characters (backslashes and newlines inside strings must be escaped), comments (JSON has no comment syntax), and a byte order mark (BOM) at the start of the file. The error message shown by this validator points to the exact location of the problem.
Is JSON the same as JavaScript object literals?
Similar but not identical. JSON is stricter: all keys must be double-quoted, values can only be strings, numbers, booleans, null, arrays, or objects. JavaScript object literals allow unquoted keys, single quotes, trailing commas, functions, undefined, and comments. JSON.parse() will reject a JavaScript object literal that uses any of these extensions.