DNS-Prefetch

Selected answers from the Dumb SEO Questions Facebook & G+ community.

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  Dave Elliott: 1. Should be. I use it all the time. Lovely little one for a tech audit
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  Andrew Raines: Same, DNS and handshake works well on driod and chrome. Just need apple to support preconnect. Apple, driod etc. support prefetch. I am not sure if preconnect and prefetch should be used. I assume not.
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  Dan Thies: 2. They’re not using the Publisher markup anymore
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  E Dieter Martin: fonts.googleapis.com gets a 404 when entered into Chrome directly. That`s probably why those tools throw the 404 as well. But I don`t think they have any business to check a "dns-prefetch". Nobody is ever following that link.
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  Michael Martinez: In general you should NOT use DNS prefetch because it wastes bandwidth and battery power on smart phones (not a problem for desktop systems). On the other hand, Google Fonts are so widely used (about 50% of the Web) that chances are good (if you use a common Google Font) they are already cached in the phones` browsers and no prefetch attempt is made anyway.
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  E Dieter Martin: Why would prefetch waste bandwidth and battery? They`ll have to make the lookup eventually. Besides, speed always comes at the expense of something else. What is more valuable speed or batteries? That is decision what to prioritize is better left to the browser or to the operating system. Is there any research out there that says that prefetch is bad? A simple Google search didn`t tell me much.
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  Michael Martinez: E Dieter Martin Prefetch pretends to make Websites fast by looking up things while the user is looking at other things. The prefetch is anticipatory and therefore sometimes loads up the browser cache with stuff the user never wants. It`s a cheap trick perpetuated on Website owners by people who didn`t stop to think about the severe impact it would have on smart phone battery life, which is already quickly degraded by all the apps people install. A slow Website is still slow even when it specifies prefetch. That`s just bad Web design masquerading as a clever idea.
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  E Dieter Martin: We are talking about DNS prefetch, right? A miniscule amount of data going back and forth? I understand the whole mechanics of it. I just can`t see why it is bad web design or "a cheap trick perpetuated on website owners". Sounds more like a conspiracy theory to me. And I still can`t find anything on Google that says DNS prefetch is bad.
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  Michael Martinez: E Dieter Martin With every Website doing that, it`s not so miniscule. Any type of prefetch is fakery. It`s anticipatory. The browser doesn`t HAVE to execute the code, but the worst-case scenario is that they are running DNS checks on everything. Some pages have dozens of prefetch scenarios. My point, though, is that it does NOT speed up anything. It SLOWS DOWN THE CLIENT by pre-emptively issuing requests for content the user hasn`t yet asked for. And it uses bandwidth that the user doesn`t necessarily want to use. It`s rude, inconsiderate, thoughtless Web design.
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  Neil Cheesman: Why is it in so many wordpress themes?
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  Michael Martinez: Neil Cheesman The short theorist`s answer is that the Web is a big, complex place and people cannot possibly anticipate every bad consequence of actions that are promoted by the crowd. I use WordPress on a lot of sites even though it is one of the worst-designed Web frameworks I`ve ever used. I use it because it`s easy to install, easy to admin, and I am a minimalist by nature anyway so I don`t load my pages up with tons of unnecessary images (although on large sites I`m as bad at creating page clutter as everyone else). I waste bandwidth and user resources, too. But I am aware I am doing that and I don`t attempt to equivocate by arguing that prefetch is a "good" thing. It`s a totally dumb, useless idea that creates a lot of unnecessary Internet traffic (AND it can be used to attack Websites, but most people don`t know how to do that and wouldn`t).
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  E Dieter Martin: I am in awe.
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  Michael Martinez: The Chrome Team just released this video today. They are introducing a concept called "Predictive Fetching", which they believe will speed up the user experience with fewer of the negative consequences of prefetching. Pay close attention to their words of caution. People need to understand that PREFETCH and PRELOAD are only meant to be used for important resources, not for all resources. And they say that Chrome won`t execute PREFETCH on 2G connections (unfortunately, they don`t address throttled 4G LTE connections, which don`t fall back to 3G and 2G). https://www.youtube.com/watch?v=03qta1Ufn3c