Performance Is Not a Checklist


I’m helping out a client who has really solid Core Web Vitals.

Their Time to First Byte, First Contentful Paint and Largest Contentful Paint are all overwhelmingly in the green. Their Cumulative Layout Shift and Interaction to Next Paint have a little room for improvement, but even those are really solid. All the usual suspects look great.

Looking at the metrics alone, you would think their performance was rock-solid and there wasn’t much to do. But in reality, they get frequent user complaints about it.

When we rolled up our sleeves and dug into those complaints a bit, a theme emerged.

These pages have a lot of content. As you scroll down into the page, that content often contains images and other forms of media and those are very large and unoptimized, resulting in them loading very slowly. (There’s a little more involved, but that’s the basic gist.)

Last week, at Smashing Conference, Carie Fisher gave a wonderful talk about accessibility. There was one phrase I that she repeated a few times that I absolutely loved: “Accessibility isn’t about conformance”.

Neither is performance.

There’s an tendency at times for organizations to treat performance as a checklist of sorts, particularly as we’ve seen the core web vitals metrics bring more attention to performance than ever before. You try to tick the box on those metrics to get them green, then call it a day. (This organization, to their great credit, did not do that.)

But none of that matters if those metrics aren’t painting a complete picture of how users interact with our sites.

Performance, like accessibility, is not about conformance.

It’s not about a checklist.

It’s not even about simply making things fast.

It’s about providing a better experience for the people using our sites and applications to make sure they can efficiently accomplish their goals. Doing that requires that we pay close attention to what those goals are, how they are trying to achieve them, and then making sure that the way we measure performance matches up.