What is wterm?

wterm, pronounced dub term, is a terminal emulator built for the web. Unlike many terminal emulators that draw everything onto a canvas, wterm renders its output directly to the DOM, which means native text selection, copy and paste, browser find, and accessibility support all work automatically without extra code. The core parsing engine is written in Zig and compiled to WebAssembly for near native performance. The project is organized as a set of packages that build on each other. The core package is a headless WebAssembly bridge with a TerminalCore interface and a WebSocket transport for connecting to a backend. On top of that sit framework specific packages: a DOM renderer for vanilla JavaScript use, a React component with a useTerminal hook, and a Vue 3 component with a template ref API. There is also an optional full featured VT emulation core powered by libghostty for applications that need complete terminal compatibility, an in browser Bash shell package, and a package for rendering Markdown inside the terminal. Feature wise, wterm supports the alternate screen buffer needed for full screen terminal apps like vim, less, and htop, keeps a configurable scrollback history, supports 24 bit color, automatically resizes using ResizeObserver, and only redraws rows that actually changed on each frame for efficiency. It ships with several built in themes, including Solarized Dark and Monokai, defined through CSS custom properties. To build wterm from source you need Zig 0.16 or newer, Node.js 20 or newer, and pnpm 10 or newer. After installing dependencies with pnpm, you compile the WebAssembly binary with zig build, then build the JavaScript packages with pnpm build. The repository includes a vanilla demo that can be served with any static file server, a Next.js example app, and a Zig test suite runnable with zig build test. wterm is released under the Apache 2.0 license.