Total Blocking Time
What is Total Blocking Time?
How Total Blocking Time is Calculated
In terms of the Total Blocking Time, any tasks that take longer than 50 milliseconds are defined as a long task. The amount of time after that is the blocking time, so for example, if a long task takes 60 milliseconds, the blocking portion would be 10 milliseconds. And like some of the previous metrics we have discussed, like the Speed Index and Tim to Interactive, the Lighthouse score represents how your pages compare to other websites when loading on mobile devices. On the Lighthouse report you will see a color-coded representation of your score. The ideal Total Blocking Time score should be under 200 milliseconds and will show up as green. Any score between 200 and 600 milliseconds (just over a half second) is considered moderately fast and will be color-coded as orange. Any Total Blocking Time score over 600 milliseconds will be color-coded red.
How to Reduce Total Blocking Time
Lighthouse is an open-source tool that is used to run an audit against your web pages and provides scores and suggestions for improving page performance, accessibility, SEO, and more.
PageSpeed Insights is a tool created by Google that reports on the performance of a page on both mobile and desktop devices, and provides suggestions on how that page may be improved.