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Analysing initial load bundle sizes using Lighthouse
Even with fast internet speeds, one key metric for improving initial page load times for websites or web apps is reducing the data transmitted over the wire. While you can optimize all kinds of assets, like styles and images, I want to focus on the size of the JavaScript bundles. Code size has an impact on download duration, but also on parsing and JavaScript execution. This can be measured as Total Blocking Time (TBT) or First Input Delay (FID), a metric suggested by Google to measure page performances as part of the Web Vitals.