Total Blocking Time (TBT) is not an actual performance metric, but by improving it, we can boost First Input Delay – the actual Core Web Vital metric.
With NitroPack, optimizations are automatically applied to help you achieve better speed and real-world performance.
How NitroPack can improve TBT (and FID) to boost performance
When you analyze your site using PageSpeed Insights or Lighthouse, in the test results, find the Diagnostics section, and click on the Avoid long main-thread tasks tab.
This will give you a list of the longest tasks on the main thread to focus on.
You can use the following NitroPack features to reduce the impact:
➡️ Minimize main thread work
By using our “Combine CSS into one resource” and “Reduce Unused CSS” features
These options will minimize main thread work and automatically compress it with GZIP, helping transfer smaller file sizes.
By using our “Combine JS into one resource” feature along with our automatic GZIP compression
➡️ Keep request counts low and transfer sizes small
By using our “Enable Font Compression Upgrade” feature
When this option is enabled, NitroPack will optimize fonts by upgrading their compression to WOFF2 format. This can reduce the size of these fonts by up to 50%.
By using our “Font Subsetting (Remove Unused Glyphs)” feature
This will remove the Unused Glyphs from the fonts used, minimizing the requests and also file sizes.
Additional information about the feature can be found in our article: