JSON stands for JavaScript Object Notation
Despite its name, JSON is language-independent and is used across virtually every modern programming language — Python, Go, Java, Ruby, PHP, and many others all handle it natively. It was named after JavaScript because it shares the same syntax for objects and arrays, but it's a universal standard, not a JavaScript-specific format.
The six data types
JSON supports exactly six value types: string (text in double quotes), number (integer or decimal), boolean (true or false), null (representing no value), array (an ordered list), and object (a set of named values). That's the entire specification.
{"name":"Ada","age":30,"active":true,"score":9.5,"tags":["engineer"],"address":null}JSON vs XML vs YAML
JSON replaced XML as the dominant web data format because it's more compact and easier to read. YAML is popular for configuration files because it supports comments and has cleaner syntax for deeply nested data, but JSON remains the default for APIs and browser storage.
Tools to work with JSON
Start with our JSON Formatter to make raw or minified JSON readable. Use the JSON Validator to check whether JSON is well-formed. The JSON Viewer renders any JSON as a collapsible tree so you can explore its structure without getting lost in brackets.
Converting JSON to other formats
Need your data as a spreadsheet? Use JSON to CSV. Want it as a configuration file? Try JSON to YAML. Need to generate TypeScript types from a JSON sample? Use JSON to TypeScript.
Frequently Asked Questions
- What is JSON used for?
- JSON is used for REST API responses, application configuration files, document databases, browser storage, and communication between services. It is the most widely used data exchange format on the web.
- Can JSON have comments?
- No — standard JSON does not support comments. If you need commented configuration, consider YAML, which supports them fully. Our JSON to YAML converter makes the switch easy.
- What is the difference between a JSON object and an array?
- A JSON object is a collection of named key-value pairs wrapped in curly braces:
{"name":"Ada"}. A JSON array is an ordered list of values in square brackets:[1, 2, 3]. Objects and arrays can be nested inside each other to any depth.