Avoid slot overuse; prefer renderless components.
Vue Define Slots Guide 2026: Master Composition API
Vue 3's define slots via Composition API supercharge component reusability in 2026 apps. This hands-on guide covers syntax, named/default slots, fallback content, and TypeScript integration for scalable UIs.
Perfect for migrating from Options API or building enterprise Vue apps. Includes code samples, pitfalls, and performance tips updated for Vue 3.5+.
Step 1: Basic Slot Definition Syntax
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Use defineSlots() in setup(). Return object with slot names.
- import { defineSlots } from 'vue'
- const slots = defineSlots({...})
- Template:
usage
Step 2: Named & Scoped Slots
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Pass data via scope params. Type-safe with interfaces.
- Fallback: () => h('p')
- v-slot:header="{ items }"
Perspective: contrast at least two practical approaches.
Step 3: TypeScript Integration
Editorial note: point out trade-offs, not only benefits.
Pros
Define SlotProps for autocomplete.
Trade-offs
Define SlotProps for autocomplete.
Define SlotProps for autocomplete.
- interface HeaderSlot { items: Item[] }
- defineSlots<{}>({ header: { type: Object as PropType
} })
Step 4: Dynamic & Conditional Slots
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Runtime slot rendering with v-if.
- computed slots()
- h(resolveDynamicComponent(), { slots })
Best Practices & Performance
Avoid slot overuse; prefer renderless components.
Avoid slot overuse; prefer renderless components.
- Memoize slot funcs
- SSR hydration
- Devtools inspection