React 18, currently in its alpha phase, can now be tested with Gatsby 3.7 by installing the alpha versions of React and React-DOM using yarn or npm. This integration allows developers to explore new features such as StartTransition, which designates certain updates as "transitions" and prioritizes urgent updates, and Automatic State Batching, which reduces unnecessary re-renders by grouping multiple state updates in asynchronous tasks. According to Ward Peeters, the Technical Lead for Gatsby Open Source, these improvements lead to enhanced performance, exemplified by a reduction in time-to-interactive (TTI) in Gatsbyjs.com. A demonstration of React 18's capabilities is available on a sample e-commerce website, and feedback is encouraged through GitHub discussions to aid further development.