SemaJSX

A lightweight, signal-based reactive JSX runtime. Fine-grained updates. No virtual DOM.

Why SemaJSX?

Simple primitives. Powerful results.

Signals automatically track dependencies and update only what changed. No virtual DOM diffing overhead.

Choose what you need: DOM rendering, Terminal UI, SSR, or SSG. All sharing the same reactive core.

Full TypeScript support with comprehensive type inference and IDE autocompletion out of the box.

Modular CSS with @semajsx/style, tree-shakeable Tailwind utilities, and signal-reactive themes.

Render to the browser DOM or the terminal. Same JSX, same signals, different targets.

Island architecture for SSR. Static site generation with MDX, collections, and incremental builds.

Everything you need to build reactive applications.

API reference and core concepts.

Step-by-step tutorials and examples.

Browse the UI component library.