Developer Tools

JSON Formatter & Validator

Paste JSON to pretty-print, minify, or validate it. If it's invalid, you'll see the exact parse error.

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Pretty-print vs. minify

Pretty-printing adds indentation and line breaks to make JSON readable for humans. Minifying strips all unnecessary whitespace to make the file as small as possible — useful when sending JSON over a network where every byte counts, but hard to read.

Common JSON mistakes this catches

  • Trailing commas after the last item in an object or array
  • Using single quotes instead of double quotes for strings
  • Missing a closing brace, bracket, or quote
  • Unquoted object keys

Frequently asked questions

Why does it say my JSON is invalid when it looks fine?

A common cause is a trailing comma after the last item in an object or array, or using single quotes instead of double quotes — both are valid in JavaScript object literals but not in strict JSON.

Is my data sent anywhere?

No — parsing and formatting happen entirely in your browser using JavaScript's built-in JSON support. Nothing is uploaded.

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