📋 JSON Formatter & Validator

Format, validate, and beautify JSON data with syntax analysis — entirely client-side.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write. It is the de facto standard for APIs and configuration files.

Common JSON Errors

  • Trailing commas: JSON does not allow trailing commas after the last element JSON does not allow trailing commas after the last element in arrays or objects.
  • Single quotes: JSON requires double quotes for strings and keys JSON requires double quotes for strings, not single quotes.
  • Unquoted keys: All keys in JSON must be quoted strings All keys in JSON must be enclosed in double quotes.
  • Comments: JSON does not support comments (// or /* */) JSON does not support comments (// or /* */).

Frequently Asked Questions

What causes invalid JSON?

Common issues include: trailing commas, single quotes (use double), unquoted keys, missing commas between elements, and incorrect nesting.

Is my data safe?

Yes. This tool processes JSON entirely in your browser. No data is sent to any server.

Parses, formats, and validates JSON data with proper indentation, syntax error detection, and tree view for complex structures.

Key Facts

  • JSON is language-independent despite JavaScript origin
  • 70%+ of public APIs use JSON
  • Supports 6 data types: string, number, object, array, boolean, null
  • Formalized in RFC 7159 (2014)

Frequently Asked Questions

What is JSON?

JavaScript Object Notation — lightweight data interchange format. Standard for web APIs, configs, and data storage.

How to validate JSON?

Must start with { or [, use double quotes, no trailing commas, properly nested. Paste here to validate.

JSON vs XML?

JSON is more compact, readable, and faster to parse. JSON standard for REST APIs, XML for SOAP services.

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