In an effort to offering superior experience to your customers, Being a test engineer, It’s no harm in knowing common browser-level performance indicators of websites. Trust me, any further you will never say, “Our website is too slow since this morning.”, but rather this way — “LCP takes 6 seconds to load” (pun intended).
Anyway, in this serious of blogs, I’ll summarise a few significant performance metrics, each of which captures certain aspect of page load speed, and in fact, working towards improving them can go a long way in achieving seamless customer experience.
Make every interaction counts, even the small ones. They are all relevant. — Shep HyKen
First Contentful Page (FCP) — The time from when the page starts loading to when any part of the page’s content is rendered on the screen; the “content” refers to text, images (including background images), <svg> elements, or non-white <canvas> elements.
Largest Contentful Page (LCP) — The render time of the largest image or text block visible within the viewport, relative to when the page first started loading.
Total Blocking Time (TBT) — The total amount of time between First Contentful Paint (FCP) and Time to Interactive (TTI) where the main thread was blocked for long enough to prevent input responsiveness. This is to say, the blocking time of a given long task is its duration in excess of 50 ms and the total blocking time for a page is the sum of the blocking time for each long task that occurs between FCP and TTI.
Time to Interative (TTI) — The time from when the page starts loading to when its main sub-resources have loaded and it is capable of reliably responding to user input quickly.
Speed Index (SI) — This measures how quickly the contents of a page are visibly populated. Speed Index is dependent on size of the viewport and expressed in milliseconds: the lower amount of time the better the score.
Cumulative Layout Shift (CLS) — This measures how much a webpage unexpectedly shifts during its life. For example, if a website visitor loaded a page and, while they were reading it, a banner loads and the page jumps down, that would constitute a large CLS score.
In a concluding note, apparently there are also other aspects of CX such as accessibility, SEO etc. that are to be considered, however, the scores of these performance metrics surely tell a lot of stories about a responsiveness of any customer facing company’s website that is in pursuit of customer retention and conversion.
Let’s also dive in to know as to how to capture these metrics, along with the remedials realtime by incorporating Google’s lighthouse within an automation project in my next blog post. It’s enough for now, and I believe you find this post insightful and helpful;
Thank you for reading!
