Research by NCC Group has found that webpages that contain a lot of third-party content load much slower than sites with less third-party content.
It looked at the 50 biggest retail sites in the UK and compared how fast their homepages displayed.
It found that the slowest website had 7.5 times more third-party content than the fastest website; the slowest website contained 618KB of third-party content, compared to 83KB on the fastest website.
Third-party content is typically advertising, remarketing or testing services.
Website loading speeds are extremely important. A report from Nielsen found that 47% of people expect a website to load within 2 seconds, and 40% will leave a website if it does not load fully within 3 seconds.Â
