โก Note: since December 2019 GOV.UK requires explicit opt-in for tracking which introduces bias. This is especially true for mobile devices, since the cookie banner takes up more screen estate and is more likely to be accepted.
Users - GA definition based on cookies:
- Safari - 45.09%
- Chrome - 37.98%
- Edge - 7.04%
- Samsung Internet - 4.81%
- Safari (in-app) - 1.39%
- Android Webview - 1.33%
- Firefox - 1.27%
- Internet Explorer - 0.59%
- Amazon Silk - 0.25%
๐งตAs I mentioned last week GOV.UK removed jQuery as a dependency for all frontend apps, meaning 32 KB of minified & compressed JS was removed. So let's see what difference this has made for users by examining our RUM data. Thread will mainly focus on JS CPU time.
A good place to start is users on low spec devices. The Universal Credit sign-in page shows a lot of this traffic, as seen in the images below.
We see many of our key metrics trending down (for p75) after the change, including frontend time, First CPU Idle, JS Long Tasks