Dadroit is a brilliant tool that threats JSON as a Data format, not a plain text. It provides you quick outline view, with the help of tree representation. You can browse and query JSON like an enterprise DBMS. It beats all of the other solutions in performance, and it will give you a complete set of tools to work too. Tree highlighted view, Instant search including RegEx support, auto-refresh on file change and many export options including XML is just a part of its features. It is Free and available for download for Mac and Windows right now, and Linux version is on the way.