Svelte 5 Has a Free API You've Never Heard Of
javascript
dev.to
Svelte 5 introduces Runes — a new reactivity system that replaces the old $: syntax with explicit, composable primitives. It's the biggest Svelte update ever, and the new APIs are incredibly powerful. What's New in Svelte 5? Runes — $state, $derived, $effect replace reactive declarations Fine-grained reactivity — only what changed updates Universal reactivity — works in .svelte AND .ts files Snippets — reusable template fragments Event attributes — onclick instead of on:click