JSON Formatter & Validator

Format, minify and validate JSON instantly — with precise error location.

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What is JSON?

JSON (JavaScript Object Notation) is a lightweight, human-readable, easy-to-parse data format. It has become the standard data format on the web — used for REST APIs, config files, and NoSQL databases.

This tool helps tidy up hard-to-read JSON strings (e.g. from API responses), minify for production, and locate syntax errors with exact line and column information.

Features

  • Format — pretty-print with 2 / 4 spaces or tabs
  • Minify — strip all whitespace for the smallest size
  • Validate — syntax check with line/column on errors
  • 100% local — no upload, no server, no logs

JSON syntax in a nutshell

JSON is strictly specified (RFC 8259). Common gotchas that cause parser errors:

  • Strings must be wrapped in double quotes, not single
  • Object keys must also be in double quotes
  • No trailing commas allowed — no comma after the last element
  • Comments are not part of the JSON spec