This page offers an easy way to visualize a string of JSON text. Put some JSON into the text area, and this page will instantly display the text as a set of nested boxes, corresponding to the objects, arrays and values in the JSON string.
You can also paste a URL into the textarea, and the JSON string will be loaded from the URL.

JSON 2 HTML is open source and released under the MIT license - get the source on github. Patches / improvements are welcomed!

JSON

Quoting from the home page of JSON
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.

Syntax Highlighting

Colour for text and null values.
Colour for numbers.
Colour for true and false values.
Colour for void values.
Background for Objects.
Background for Arrays.
Background for Object name/value pair tables.
Background for Array value tables.

Note

Individual 'words' that are extremely long may be broken into two or more lines to conserve horizontal space.