Six things that slow down your site’s UX (and why you have no control over them)

Have you ever looked at the page speed metrics – such as Start Render and Largest Contentful Paint – for your site in both your synthetic and real user monitoring tools and wondered “Why are these numbers so different?”

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Your synthetic testing tool shows you how your pages perform in a clean lab environment, using variables – such as browser, connection type, even CPU power – that you’ve selected.

Your real user monitoring (RUM) tool shows you how your pages perform out in the real world, where they’re affected by a myriad of variables that are completely outside your control.

In this post we’ll review a handful of those performance-leaching culprits that are outside your control – and that can add precious seconds to the amount of time it takes for your pages to render for your users. Then we’ll talk about how to use your monitoring tools to understand how your real people experience your site.

Source: Six things that slow down your site’s UX (and why you have no control over them)