For a web design to be successful, it needs to be fast & responsive to do well on mobile, and intuitive so users find what they need quickly.
I remember as a kid the five second rule. If food fell on the floor, it was still ok to eat it if was on the ground for less than five seconds.
Turns out that germs are more forgiving than mobile users. There is not broad agreement, but it seems they follow the under three second rule.
If a page takes over 3 seconds to load, mobile users bounce as the Pingdom chart below suggests.
SEMRush gauges page speed using a 1 second rule. I would argue they are closer. My personal experience suggests that the widow has continued to narrow.
Search engines grade your speed as part of your ranking. Therefore, page speed is an important factor in search engine optimization.
The root cause of most speed issues is the content management system (CMS) that you choose for your website.
In plain English, these are programs such as WordPress and Wix. These programs have three parts.
The browser has to fetch the data and the full theme in order to render the page. After the browser parses the content, it has to sort through all of the themes features to see which to use. This causes delays in loading, which is typically called render blocking CCS.
With all these disadvantages, you might ask why someone would choose a CMS. A CMS is user friendly. They are faster to build, easier to maintain, and simpler to update. You do not need to understand coding or even basic HTML or CSS commands to get great looking results.
The key issue with the theme. Every theme carries a set of instructions called cascading style sheets (CSS), which tell the browser how the page should look. It will load your content onto the screen following these instructions.