Preact offers an API which is extremely similar to React's for less than 10% of its size (and createElement is renamed to h, which makes the overall bundle a lot smaller). Although it is less compatible with other libraries than the latter (and its ecosystem is nowhere as developed), this is generally not a problem as Preact exposes the preact/compat API, which can be used as an alias both for React and ReactDOM and allows for the use of libraries which would otherwise just be compatible with React.