I was reading John Resig’s Browser Page Load Performance post earlier today and followed up from there on the concept of Link prefetching. Currently supported by Firefox 2+, Link prefetching is a browser based mechanism for fetching “future” content. Considering I wrote (and ultimately scrapped*) similar functionality for my gallery pages, I was obviously intrigued.

In its basic version it looks like this:

<link rel="prefetch" href="/images/big.jpeg">

With the href being the target content and the rel attribute triggering the prefetching mechanism. Pretty simple. I’ve already implemented it here on my gallery pages.

One thing I would like to see, and this is hinted at on the above linked Mozilla FAQ page, is prefetching performed automatically on anchor (<a>) tags with rel attribute set appropriately. In my mind that would be any anchor with a rel attribute of next, but the prefetch value would be fine as well. Personally, if that were supported I wouldn’t have any (or very little) work to do to take advantage of this feature and in a general sense it would build on what people are already doing using prev, next and toc rel attributes on gallery links.

*it was scrapped because I hated the idea of forcing bandwidth usage on people with metered accounts. Since this is a browser based mechanism, it should be relatively painless for people in that situation to control whether or not content is prefetched.