There is a also a nice little plugin for firefox ( JSON View) which will pretty print the JSON. The right HTTP Content-Type would be application/json, as others already highlighted too, but some clients do not handle it very well, thats why jQuery recommends the default text/html. When using the JSON format to communicate with the server we must set one fof the following as the http content-type headerPlain text. No HTML tags allowed. Lines and paragraphs break automatically.