JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is 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, including C, C++, C#, Java, JavaScript, Perl, Python, and many others. These properties make JSON an ideal data-interchange language.

You can use this tool to validate, beautify or to flatten the JSON string.

You can add Chrome App to your browser to validate and beautify the JSON.