// the find
preactjs/preact
⚛️ Fast 3kB React alternative with the same modern API. Components & Virtual DOM.
Preact is a 4kB virtual DOM library that mirrors the React API closely enough that most React code runs unchanged via the preact/compat shim. It exists for one reason: bundle size. If you're shipping to users on slow connections or constrained devices and React's 45kB is genuinely hurting you, this is the serious alternative.
The diff algorithm is genuinely fast and well-tested — the benchmark suite and CI workflows show this is treated as a first-class concern, not an afterthought. The preact/compat layer is surprisingly complete: Suspense, portals, forwardRef, hooks, scheduler shim — all there, all tested against the same cases React tests. The monorepo structure is clean and the package boundaries make sense (core, hooks, compat, debug are separate packages). Active maintenance with a commit as recent as yesterday suggests the project isn't coasting.
The compat layer is where you'll hit friction: it's React-like, not React-identical, and edge cases in things like synthetic events and concurrent mode features will bite you when migrating a real app. The README is sparse for a library of this maturity — it sends you to an external website for anything beyond hello world, which is fine until that site changes. There's no native equivalent to React Server Components and the async rendering story diverges meaningfully from React 18/19, so if your team is moving toward RSC or the new concurrent patterns, preact/compat won't save you from a full rethink.