Can I change all my http:// links to just //?

Question

Dave Ward says,

It’s not exactly light reading, but section 4.2 of RFC 3986 provides for fully qualified URLs that omit protocol (the HTTP or HTTPS) a

Answer 1

Is this completely cross-browser compatible? Are there any other caveats?

Just to throw this in the mix, if you are developing on a local server, it might not work. You need to specify a scheme, otherwise the browser may assume that src="//cdn.example.com/js_file.js" is src="file://cdn.example.com/js_file.js", which will break since you're not hosting this resource locally.

Microsoft Internet Explorer seem to be particularly sensitive to this, see this question: Not able to load jQuery in Internet Explorer on localhost (WAMP)

You would probably always try to find a solution that works on all your environments with the least amount of modifications needed.

The solution used by HTML5Boilerplate is to have a fallback when the resource is not loaded correctly, but that only works if you incorporate a check:

I posted this answer here as well.

UPDATE: HTML5Boilerplate now uses