When comparing Preact vs Cycle.js, the Slant community recommends Cycle.js for most people. In the question“What are the best React.js alternatives?” Cycle.js is ranked 5th while Preact is ranked 11th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Lightweight
The size when gzipped is only 3kb, and performance is as good as (or even faster than) React itself.
Pro Same API as react
Avoids having to learn an entire new paradigm, and makes it easy to switch between the two libraries later on.
Pro Lots of examples and libraries
They have a bunch of examples and addon libraries.
Pro Awesome CLI
Preact CLI gives you a perfect scoring PWA out-of-the-box with no configuration.
Pro Not opinionated
Pro All behaviour is declared in a pure main function
Pro Functional approach
Pro Virtual DOM rendering
Pro Conceptually fascinating
A perpetual motion machine that works.
Pro Supports JSX, React Native…
Pro Server-side rendering
Cons
Con Difficult to learn
You need to be good in React JS first to learn Preact. Documentation is not rich. And some of the examples given on site are not working. Developers are not much active on Stack Overflow as well.