JSON Parser Online

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write and easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages.

Why do we need a JSON Parser and Formatter?

During development, API responses are usually returned as a single minified line of JSON string. While this is efficient for machines, it's nearly impossible for developers to read and debug. By using an online JSON Formatter, you can instantly "pretty print" messy JSON strings with proper indentation, line breaks, and syntax highlighting, greatly improving readability.

How to validate JSON online?

This tool comes with a built-in strict JSON syntax validation engine. Simply paste your code into the left input box. If there are syntax errors (e.g., missing quotes, trailing commas, unclosed brackets), the system will immediately display the specific error reason in red, helping you quickly locate and fix the issue.

Common JSON Syntax Errors

• Missing Double Quotes: In JSON, all keys and string values MUST be wrapped in double quotes "". Single quotes '' are invalid.
• Trailing Commas: There must be NO comma after the last element in an array or object.
• Invalid Data Types: JSON values can only be strings, numbers, booleans (true/false), arrays, objects, or null. Functions, Date objects, or undefined are not allowed.