Is type="text/css" necessary in a <link> tag?

I was wondering whether or not it is necessary to use <link rel="stylesheet" type="text/css" href=...> over <link rel="stylesheet" href=...>. The rel="stylesheet" marks the information that it is a stylesheet - so text/css doesn't actually add anything as far as I'm concerned.

The only stylesheet format used by HTML is CSS anyway, so what does text/css 'say' to the browser? Some websites seem to add the type="text/css" attribute (http://www.jquery.com/), whilst other ones don't (http://www.youtube.com/).

So, what is the use of type="text/css" in a <link rel="stylesheet"> element, and is it necessary to include it?

Solution 1:

It's not required with the HTML5 spec, but for older versions of HTML is it required.

Html 4 W3.org spec

http://www.w3.org/TR/html40/struct/links.html#edef-LINK http://www.w3.org/TR/html40/present/styles.html

Type stands for The MIME type of the style sheet. The only supported value I have ever seen is Text/CSS, which is probably why HTML5 has dropped it. I imagine they had it for earlier versions to allow future expansion possibilities which never happened.

Using HTML5 and not specifying the type, I have run so far into no problems with compatibility even when testing older versions of IE.

Solution 2:

It's not required, no.

The part of the HTML Living Standard you're interested in is The link element, which states:

A link element must have either a rel attribute or an itemprop attribute, but not both.

The type attribute gives the MIME type of the linked resource. It is purely advisory. The value must be a valid MIME type string.

For external resource links, the type attribute is used as a hint to user agents...