Svelte 5, a planned update to the reactive UI framework, has reached the release candidate phase. No breaking changes are anticipated between now and the stable release.
The release candidate was announced on April 30. It features a rewrite of Svelte to be faster, easier to use, and more robust. Runes, a signal-powered reactivity API, is a highlight of this release. Runes promises to unlock universal, fine-grained reactivity, the Svelte team said.
Other highlights in Svelte 5 include:
- Overhauled event handling to be more flexible with less boilerplate.
- Improvements to component composition through snippets.
- Native TypeScript support, including inside markup.
Components written for Svelte 4 will continue to work, with several exceptions. Components are no longer classes in Svelte 5. The team said that eventually, certain Svelte 4 features will be dropped in favor of modern replacements.
Svelte 5 can be accessed via the following option when starting a new SvelteKit project:
npm create svelte@latest
The Svelte 5 bulletin lists other ways to access Svelte 5.
Similar to other reactive UI frameworks, Svelte allows developers to build applications declaratively using components that combine markup, behavior, and styles. Components are compiled into small JavaScript modules that eliminate the overhead traditionally associated with UI frameworks. Developers can build an entire application using a Svelte-compatible application framework such as SvelteKit.