What is the purpose of leading slash in HTML URLs?
It's important to start a URL with a
/ so that the intended URL is returned instead of its parent or child.
Let's say if your browsing
/cream-cakes/ then you have a link on the page that has
blah.html without the forward slash it is going to attempt to visit page
/cream-cakes/blah.html while with the forward slash it'll assume you mean the top level which will be
Generally, it's best to always use
/ in my experience as its more friendly when you change the structure of your site, though there is no right or wrong assuming that the intended page gets returned.
Does the leading '/' mean the path is starting from the site root?
Technically this is referenced in section 4.2 of RFC 3986 as an "absolute-path reference":
A relative reference that begins with a single slash character is termed an absolute-path reference.
It ensures the path is absolute to the root directory and not the current directory (termed a "relative-path" reference). See this for an expanded discussion on that.
That's a root-relative link. It's a relative link (somewhat akin to
../) but it begins at the root of the site. If a page three levels deep on the site begins a link with the forward slash, the remainder of the path will be relative to the root of the site.
A benefit to this form of pathing is fewer characters in the markup:
Another advantage is portability across domain changes. If
example.com content is moved to
example.org, for example, root-relative links will still work, assuming the same directory naming/layout is used. Especially useful if developing pages locally, then uploading to the web.
As with other types of pathing - relative (
../) and absolute (
http://...) this is still subject to updating links when files or directories are renamed or moved.