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JSON Formatter & Validator

Beautify and validate JSON data — with syntax highlighting and error detection

Free Client-Side No Login No Storage
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How to Use the JSON Formatter & Validator

  1. Paste raw or minified JSON into the input field.
  2. Click Format to beautify with syntax highlighting.
  3. Use the tree view to collapse and expand individual nodes.
  4. Click any key to copy its JSON path.
  5. Use Search to find keys in large JSON objects.

What does this tool do?

The JSON Formatter validates your JSON for syntax errors and displays it in a readable, indented format with colour-coded keys, strings, numbers, and booleans. The collapsible tree view lets you navigate large JSON structures without scrolling through thousands of lines.

What is a JSON Formatter?

A JSON formatter (also called JSON beautifier or JSON prettifier) takes minified or unformatted JSON and adds proper indentation and line breaks to make it human-readable. JSON (JavaScript Object Notation) is a lightweight data format widely used in APIs, config files, and data storage.

Common Uses

  • Formatting API responses for debugging and readability
  • Validating JSON structure before using it in code
  • Prettifying JSON config files (package.json, tsconfig.json, etc.)
  • Inspecting nested JSON objects and arrays from logs

Frequently Asked Questions

How do I validate JSON online?

Paste your JSON into the formatter. If it contains errors, the validator will highlight the exact line and character where the syntax breaks. Common errors include trailing commas, unquoted keys, and single quotes instead of double quotes.

What is the difference between JSON and JavaScript objects?

JSON is a strict text format — all keys must be double-quoted strings, trailing commas are not allowed, and functions are not supported. JavaScript objects are more flexible and are runtime constructs, not text.

What does "unexpected token" mean in JSON?

It means the parser found a character it didn't expect. Common causes: a trailing comma after the last item in an array or object, single quotes instead of double quotes, or an unquoted key name.