Across the data set, we manually classified each site into one of the following categories:
• Banking & Financial Services
• General Services
• Government & Non-Profit
• New & Media
• Travel & Leisure
The ‘Other’ category is a group of 95 sites that did not fit neatly into any of the above categories, and had not enough peers with which to make a robust additional category. The distribution of sites across the categories is as follows:
Across the whole data set 88% serve content optimised for mobile viewports, meaning 12% of the top UK websites are still not responsive to mobile device users. 56% of sites served content via HTTPS protocol, and in terms of speed on 3G, just half managed to get some interactivity in less than 10 seconds. The sites analysed performed very poorly on the newer truly progressive features; only 1% installed a service worker and only 2 websites (0.27%) in the whole data set made use of an Add to Home Screen feature.