Web performance analysis of top 10 supermarket websites in Denmark


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...

Slow mobile websites are a business problem, not engineering


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...

Web performance cost of unused CSS


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...

Apple Safari 14 will support WebP image format


github.pie.apple.com or why you should configure referrer policy for internal company websites


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...

Older posts