TRUTHY TOOLS

JSON Formatter & Validator

Pretty-print, minify, and validate JSON in the browser with clear parsing errors and one-click output copy actions.

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About this tool

JSON Formatter helps developers, API testers, data analysts, and support teams pretty-print, minify, validate, and copy JSON with clear parsing errors. Use it for API response formatting, webhook payload review, fixture cleanup, config validation, and LLM JSON output checks.

Use cases

  • Paste a compact API response and pretty-print it so nested objects, arrays, booleans, nulls, and numbers are easy to inspect in a bug report.
  • Minify formatted JSON before adding it to a request body, fixture, environment variable, or command-line example that needs a compact payload.
  • Use parsing errors to find missing commas, trailing commas, unquoted keys, invalid escapes, or mismatched braces in a broken JSON snippet.
  • Copy clean JSON output into API docs, QA notes, support replies, Postman examples, curl commands, or pull request descriptions.

FAQ

What is JSON Formatter best used for?

JSON Formatter is best used to pretty-print, minify, validate, and copy JSON while working with APIs, configuration, fixtures, logs, and webhooks.

What input and output should I expect?

Paste valid JSON text or a JSON snippet you want to validate. The tool returns formatted or minified JSON when parsing succeeds, or a clear parsing error when the input is invalid.

Why does JavaScript-like object syntax fail?

JSON is stricter than JavaScript object literals: keys must be double-quoted, strings must use double quotes, comments are not allowed, and trailing commas are invalid.

What JSON validation edge cases should I check?

Check the reported area for missing commas, extra commas, invalid escape sequences, smart quotes, unclosed brackets, unsupported comments, trailing commas, or pasted log text before and after the JSON payload.