Now that we have JSON, why do people still use XML for new web services?

Question

Possible Duplicate:
What are the pros and cons of XML and JSON?

I don't know of a web facing language that doesn't support both JSON and XML. So I'm sure this has nothing to do with serving different formats because of needs.

My guess is that people are still making new web services using XML because that's what they know, or the web service was built before JSON was well known. However, regardless of what I think...

Are there somethings that JSON can't do which is why people still use XML as the format for new things? I personally started with XML but when JSON came out I made the switch since:

• JSON is easier to process (a lot less rules about syntax)
• JSON is smaller (and bandwidth matters!)

Any answer that shows a XML fitting a API use-case better than JSON is good enough for me.

Answer 1

XML is better for data interchange between systems because it is very well understood and human readable (making interpreting easier for you).

Source.

Also see this question.

Answer 2

An article I read a while back indicated the following but I unfortunately cannot find the source nor been able to find anything that validated or refuted the claim.

It seems that both YAML and JSON are faster to encode for up to about 5000 elements, then XML takes over. It also looks like both YAML and JSON require twice as much memory as XML when decoding.

Answer 3

JSON is "only" a format for data exchange. XML is more powerful because of it includes a data type description (DTD) as well.

But I think you are right: In most cases a simple data exchange format like JSON fits best.

Answer 4

Sometimes it is very important to have a rich validation of input data. For the purpose the usage of XML Schema (XSD), XPath or XSLT is very practical. There are of cause some approaches for JSON Schema but the technique has mostly draft label and in not a well-known and used standard like XSD.

So in some cases I use JSON (also JSON only without XML support) and in another cases I do use XML with XML Schema.