what is difference between text/javascript and application/javascript [duplicate]

Answer 1

HTML 4.01 (1999) specification suggests using MIME type text/javascript (http://www.w3.org/TR/1999/REC-html401-19991224/interact/scripts.html#h-18.2.2.2).

However, RFC 4329 (2006) now recommends the use of application/javascript.

It seems that historically text/javascript was used a lot and since it was the type that browsers most likely supported, this was the type that got suggested also in the HTML specification. Ideally, you would use application/javascript.

In practice you may need to use text/javascript to provide compatibility with less-conforming browsers.

Answer 2

text/javascript was introduced when the web was young and people hadn't thought things through.

Then people thought things through, and decided that text/* should be reserved for things designed to be human readable (which is why some XML is text/xml and other XML is application/xml). JavaScript is not human readable, so text/javascript was deprecated and application/javascript was introduced to replace it.

Years later, some browsers still haven't caught up.

You can configure your server to always serve application/javascript in the HTTP headers; browsers that don't support it also pay no attention to the actual content-type.

For the time being, if you are writing HTML 4 or XHTML 1, specify text/javascript in the type attribute for the sake of backwards compatibility. If you are writing HTML 5, then omit the type attribute (as it is now optional).