{} JSONFormat

Working with JSON

JSON (JavaScript Object Notation) has become the universal data format of the web, used by over 95% of REST APIs. Its simplicity — just objects, arrays, and six primitive types — makes it both powerful and easy to get wrong. A single missing comma, trailing comma, or unescaped quote can break an entire API response.

JSON was formalized by Douglas Crockford in 2001 and standardized as ECMA-404 in 2013. Despite its name, JSON is language-independent and has parsers in every major programming language. A 2024 survey found that developers spend an average of 47 minutes per week debugging malformed JSON.

Common JSON Mistakes

• Trailing commas in arrays/objects — valid in JS but invalid in JSON
• Using single quotes instead of double quotes for keys and strings
• Unescaped backslashes or control characters in string values
• Comments — JSON does not support comments (use JSONC or JSON5 if needed)