Link prefetching FAQ
developer.mozilla.org
developer.mozilla.org
> prefetching is a browser feature; users should be able to disable it easily.
can be preceded so closely by this:
> there is a hidden preference that you can set to disable link prefetching.
> However, the theory is that if link prefetching needs to be disabled then there must be something wrong with the implementation.
And later:
> Privacy implications
> Along with the referral and URL-following implications already mentioned above, prefetching will generally cause the cookies of the prefetched site to be accessed. (For example, if you google amazon, the google results page will prefetch www.amazon.com, causing amazon cookies to be sent back and forth.
I honestly can't see this feature doing anything more than harm. Every site has it in their interest to declare every link as pre-fetched, because it will make that site "seem faster". And this will cost every user a lot of hidden bandwidth and cache. Am I crazy?
This technique is useful for a multipage process, or some other flow where there is, say, 50+% chance that the user will go to a specific page. It can be verified through analytics.
HTTP/2's Server Push implements this concept at the protocol layer.