Vite 8.1 brings faster dev mode, chunk import maps, and Wasm ESM support

Vite 8.1 introduces experimental bundled dev mode, designed to improve development performance in projects with many modules. In internal testing on an app with 10,000 React components, the Vite team saw up to 15 times faster startup and 10 times faster full page reloads compared to the traditional unbundled server. The mode is still experimental and currently focuses on browser side behavior and core Vite features, so some third party plugins and minor features may not work yet.

Early real world testing showed similar gains. Linear reported up to three times faster cold start rendering, reloads around 40 percent faster, and 10 times fewer network requests. Developers can enable bundled dev mode with the --experimental-bundle flag or by setting experimental.bundledDev: true in their configuration.

The release also adds an experimental chunk import map feature for production builds, using import maps to reduce cascading hash changes and improve cache efficiency, though experimental.renderBuiltUrl is not supported yet. Vite 8.1 also brings native support for the WebAssembly ECMAScript Module integration proposal, allowing .wasm files to be imported and used directly in JavaScript.