Svelte 5 Runes

A guide to Svelte 5's runes system for explicit, composable reactive declarations that replace implicit reactivity.

Usage

Ask about Svelte 5 runes, migration from Svelte 4, or new reactivity patterns.

Examples

• "Convert a Svelte 4 component to use runes"
• "How does $derived replace $: reactive statements?"
• "Create a reusable reactive utility with $state"

Guidelines

• Use $state for reactive variable declarations
• Use $derived for computed values replacing $: labels
• Use $effect for side effects replacing reactive statements
• Use $props for component prop declarations
• Runes work in .svelte.js files for non-component logic