I have analyzed mobile website performance of the top 10 supermarkets in Denmark. My goal has been to assess the state of mobile web performance in a less explored niche that is still visited by many people every day. I have summarised common performance bottlenecks across websites and identified top performance improvement opportunities for each website. I have divided analysis into overall technical comparison based on PageSpeed field data and my unique observations. Data has been collected on 8th of July, 2020. Continue reading...

More than 50% of all website traffic has been mobile since 2017 (ref). I can relate to this statistic looking at my own browsing habits. I do most of the web browsing on my smartphone. Even when a laptop or TV with a larger screen is a few meters away. For me, convenience outweighs reduced screen size.

Unfortunately, very few businesses relate to the shifted web browsing trends. Most business websites have not progressed beyond responsive layout. For a small part, it might be due to general lack of good craftsmanship in the web dev field, but for the most part it boils down to business priorities, because good performance and good UX does not come for free. Continue reading...

Unused CSS is a sneaky problem. New website project usually starts with a few lines of highly specific CSS. Project time is short, so a decision is made to save time on basic component styling by adding Bootstrap or a couple similar UI libraries and suddenly CSS file grows above 10000 lines. Currently, Bootstrap is around 10000 lines of CSS before minification. Continue reading...

Only a couple months ago I was pointing out the irony of Safari not supporting WebP image format and its impact on Apple homepage loading speed. Fast forward to WWDC 2020 and Apple announces Safari 14 Beta version with WebP image format support. Continue reading...

Let’s start with a disclaimer that I have no knowledge if github.pie.apple.com is a legitimate domain belonging to Apple. If it does, it shows that Apple engineers are all in on Apple Pie puns. Continue reading...