React.lazy, Suspense and the Hidden 300 ms Delay

React.lazy, Suspense and the Hidden 300 ms Delay

An analysis of React’s lazy loading and Suspense mechanisms reveals an undocumented 300‑millisecond pause before the fallback component appears. The delay, introduced to avoid flickering during rapid loading, can affect perceived responsiveness. The article explains the rationale, demonstrates how to measure the latency, and offers strategies for developers to mitigate its impact on user experience.