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+---
+title: KeepAlive Component Best Practices
+impact: HIGH
+impactDescription: KeepAlive caches component instances; misuse causes stale data, memory growth, or unexpected lifecycle behavior
+type: best-practice
+tags: [vue3, keepalive, cache, performance, router, dynamic-components]
+---
+
+# KeepAlive Component Best Practices
+
+**Impact: HIGH** - `<KeepAlive>` caches component instances instead of destroying them. Use it to preserve state across switches, but manage cache size and freshness explicitly to avoid memory growth or stale UI.
+
+## Task List
+
+- Use KeepAlive only where state preservation improves UX
+- Set a reasonable `max` to cap cache size
+- Declare component names for include/exclude matching
+- Use `onActivated`/`onDeactivated` for cache-aware logic
+- Decide how and when cached views refresh their data
+- Avoid caching memory-heavy or security-sensitive views
+
+## When to Use KeepAlive
+
+Use KeepAlive when switching between views where state should persist (tabs, multi-step forms, dashboards). Avoid it when each visit should start fresh.
+
+**BAD:**
+```vue
+<template>
+  <!-- State resets on every switch -->
+  <component :is="currentTab" />
+</template>
+```
+
+**GOOD:**
+```vue
+<template>
+  <!-- State preserved between switches -->
+  <KeepAlive>
+    <component :is="currentTab" />
+  </KeepAlive>
+</template>
+```
+
+## When NOT to Use KeepAlive
+
+- Search or filter pages where users expect fresh results
+- Memory-heavy components (maps, large tables, media players)
+- Sensitive flows where data must be cleared on exit
+- Components with heavy background activity you cannot pause
+
+## Limit and Control the Cache
+
+Always cap cache size with `max` and restrict caching to specific components when possible.
+
+```vue
+<template>
+  <KeepAlive :max="5" include="Dashboard,Settings">
+    <component :is="currentView" />
+  </KeepAlive>
+</template>
+```
+
+## Ensure Component Names Match include/exclude
+
+`include` and `exclude` match the component `name` option. Explicitly set names for reliable caching.
+
+```vue
+<!-- TabA.vue -->
+<script setup>
+defineOptions({ name: 'TabA' })
+</script>
+```
+
+```vue
+<template>
+  <KeepAlive include="TabA,TabB">
+    <component :is="currentTab" />
+  </KeepAlive>
+</template>
+```
+
+## Cache Invalidation Strategies
+
+Vue 3 has no direct API to remove a specific cached instance. Use keys or dynamic include/exclude to force refreshes.
+
+```vue
+<script setup>
+import { ref, reactive } from 'vue'
+
+const currentView = ref('Dashboard')
+const viewKeys = reactive({ Dashboard: 0, Settings: 0 })
+
+function invalidateCache(view) {
+  viewKeys[view]++
+}
+</script>
+
+<template>
+  <KeepAlive>
+    <component :is="currentView" :key="`${currentView}-${viewKeys[currentView]}`" />
+  </KeepAlive>
+</template>
+```
+
+## Lifecycle Hooks for Cached Components
+
+Cached components are not destroyed on switch. Use activation hooks for refresh and cleanup.
+
+```vue
+<script setup>
+import { onActivated, onDeactivated } from 'vue'
+
+onActivated(() => {
+  refreshData()
+})
+
+onDeactivated(() => {
+  pauseTimers()
+})
+</script>
+```
+
+## Router Caching and Freshness
+
+Decide whether navigation should show cached state or a fresh view. A common pattern is to key by route when params change.
+
+```vue
+<template>
+  <router-view v-slot="{ Component, route }">
+    <KeepAlive>
+      <component :is="Component" :key="route.fullPath" />
+    </KeepAlive>
+  </router-view>
+</template>
+```
+
+If you want cache reuse but fresh data, refresh in `onActivated` and compare query/params before fetching.