I just watched an ironically-long lecture by Google’s Ilya Grigorik who is part of their Make the Web Faster initiative. Most fascinating lecture I’ve heard, maybe. You might want to watch it too; but if not, let me try to give you the takeaways. You could have guessed the gist of this, but not its severity: The longer your site or app takes to load or respond, the more your engagement, bounce and ultimately retention, overall traffic and business will suffer, and every hundredth of a second makes a measurable difference, heavily so with general latency exceeding one second. Therefore, it should be among your top priorities to make your site or apps respond to user stimuli as seemingly-instantaneously as possible (ideally inside 1000ms). That’s the takeaway.
Especially as the size of webpages increase faster than the average Internet connection increases over time, we need to make the web faster not just because fast is fun or so that Google’s Search and Chrome can compete better with Microsoft’s Bing and IE but because based on studies by Google, by Microsoft and others, a site’s bounce rate increases significantly, specifically 0.65%, for each additional second it takes to load. Meaning the longer your site takes to load, the more traffic you’ll lose, the worse conversion rates you’ll have, the worse user experience you’ll deliver and so forth. Especially, especially with mobile users, a portion of your visits that you’ll continue to find expanding each month.
Google found that a delay as short as 400ms would lower the number of searches per user by 0.6%. Microsoft, after seeing what happens when slowing down Bing for a set of users with delays between 50ms through 2000ms, discovered that, for example, if they add a 2000ms delay, they make 4.3% less revenue per user. In an industry of thin margins on a large scale, that’s an enormous loss. Perhaps more significantly, with the additional 2000ms, after the page finishes loading users take over three seconds longer to click something, meaning visitor distractibility rises exponentially with the time it takes to load your site. And even after a period of five weeks of restored performance, Google saw that the damaged engagement figures across the board did not heal toward what they had been, therefore slowness creates permanent damage. Those visitors were shell-shocked, digitally scarred for life. Latency PTSD.
Whether it’s video games, VoIP RTTs, web apps or websites, Ilya Grigorik proposes that this is true and will remain true, that users perceive a complete response to what they do inside 100ms to be instantaneous. Nudging that delay up to 300ms, that feels sluggish. Up to 1000ms, mildly irritating, but still engaged. Now, above one second, users start thinking about other things, then they might go pursue one of those things rather than your site. If you make them wait over ten seconds, you’ll lose them. Goodbye. Stay inside 1000ms, at least for the immediately-visible and necessary components of your site or application. That should be your goal, even with mobile devices, hence his lecture’s title “Breaking the 1000ms Glass Mobile Barrier.”
Breaking that barrier is very challenging, even on a simple-looking page like google.com, almost impossible with phones. (If you’re interested in the technical end of why or you want to try to invent 5G, watch the video.) Fortunately, there are many ways to make your site load much faster without sacrificing any usability or even cosmetics. Actually, this page right here, the one that you’re reading, is taking more than ten seconds to load fully by my watch, and that’s very unacceptable according to what I’m writing about. This site is a perfect example of something that desperately needs improvement in terms of speed, and that might be toward the top of reasons our traffic has been suffering greatly. If this man knows what he’s talking about, improving our traffic and user experience substantially, fortunately, will be fairly easy, given that there are so many things we are doing wrong that are not that challenging to correct.
I intend to practice what I’m preaching and trim that fat down, and the first stop I’m going to use, and you may want to use if you run a website (unless you don’t want traffic and happy visitors), is Google Developers’ Make the Web Faster resource. If you want a thicker and more advanced resource, check out Ilya’s site, which, as you might expect, loads pretty fast (faster than google.com, actually), and it just might break that 1000ms barrier for you — if, and only if, you use a SPDY-capable browser (or live in Mountain View).