When to use Xml and when to use JSON

 

XML	JSON
You need message validation	You don't need Messages to be validated
XML transfer is slower then JSON since the file size is relatively compared to JSON.	JSON is a good if you want to transmit data faster from client to server, due to reduced file size
You need to transform the XML i.e. if  using XSLT	You're not transforming messages, or transforming their de serialization is simple
Your messages include a lot of marked-up text	Your messages are mostly data, not marked-up text
You need to interoperate with environments that don't support JSON	The messaging endpoints have good JSON tools
Used when objective is to carry or store data	Used when objective is to display the Data
When there is no concern for reduced file/transfer size.	When there is a requirement for reduced file/transfer size.
Processing is slower since XML has to be parsed with XML parser.	Processing is faster since JSON can be parsed by a standard JavaScript function.