When serving JavaScript files, is it better to use the application/javascript or application/x-javascript

Question

The whole question fits in the title. And to add some context: I'm not asking what is the best according to what the specs are saying, but rather what works the best given the mix of browsers deployed nowadays.

Some data points:

• Google uses text/javascript for the JS used on their home page.
• Google uses text/javascript on Google Docs.
• Google uses application/x-javascript to serve JavaScript files with their Ajax libraries service.
• Yahoo uses application/x-javascript to serve their JS.
• Yahoo uses application/x-javascript for the JavaScript served on their home page.

Answer 1

In most situations, the mime type the server sends makes no practical difference. I would go with application/javascript, which is also recommended by an RFC.

Answer 2

It has been "text/javascript" but this is obsolete (see the IANA List) and now it should be "application/javascript" (see another IANA List).

Answer 3

• text/javascript - is obsolete
• application/x-javascript - was experimental while deciding to move to ...
• application/javascript is the current official MIME type for JS

That said, browsers ignore the content-type sent by the server and pay too much attention to the type attribute (and many don't yet recognise application/javascript).

My recommendation:

• Use application/javascript on the server
• Use text/javascript as a hack in type attributes in HTML documents