CSS: protocol-relative URL
Protocol relative URL is a URL without the http:
or https:
. For example, you write
<a href="//google.com/">google</a>
This can be used in CSS too.
/* use protocol-relative url starts with 2 slashes*/ div.xyz {background:url(//example.org/logo.png)}
Browser will use http:
or https:
automatically, depending which is used in current page.
protocol-relative URL for Local File
One problem with protocol relative url is that links to external sites will no longer work for local HTML files. For example, if you sell a book in HTML format. links like //example.org/
will not work.