Chapter 67: Vue $forceUpdate() Method
This.$forceUpdate() (Options API) or instance.proxy.$forceUpdate() / getCurrentInstance().proxy.$forceUpdate() (Composition API)
This method is not part of the Composition API philosophy, and in modern Vue 3 code written with <script setup>, you almost never need it — and when you do see it, it’s usually a red flag that something is wrong with how reactivity is being used.
But it still exists, it’s still documented, many legacy projects use it, and interviewers sometimes ask about it, so we need to understand it properly.
1. What does $forceUpdate() actually do?
It tells Vue:
“I know you think nothing changed, but please re-render this component and all its children right now, even though your reactivity system didn’t detect any change.”
In other words: it forces a full re-render of the component instance, bypassing Vue’s normal reactivity-based update detection.
Important: It does NOT re-run setup(), data(), computed watchers, or lifecycle hooks. It only triggers a render + patch operation.
2. When do people think they need $forceUpdate()?
These are the most common situations where beginners (and sometimes experienced developers) reach for it:
- You mutated an object/array in a way that Vue cannot detect (very common mistake)
- You replaced a reactive object with a new one without using reactive() or ref()
- You used a non-reactive third-party library and changed its internal state
- You directly mutated DOM and want Vue to “see” it (almost never correct)
- You used Object.freeze() or other non-reactive patterns
- You changed something inside a deeply nested object without reactive deep tracking
All of these are usually symptoms of broken reactivity, not reasons to use $forceUpdate().
3. Classic Bug That Makes People Reach for $forceUpdate() (and the correct fix)
Buggy code (very common mistake)
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<template> <div> <p>Items: {{ items.length }}</p> <button @click="addItem">Add Item</button> <ul> <li v-for="item in items" :key="item">{{ item }}</li> </ul> </div> </template> <script setup> import { ref } from 'vue' const items = ref(['Apple', 'Banana']) // WRONG: push on plain array – Vue cannot detect it! function addItem() { items.value.push('Cherry') // ← reactivity lost! // items.value = [...items.value, 'Cherry'] ← this WOULD work } </script> |
→ Click “Add Item” → nothing happens (count doesn’t update, list doesn’t grow)
Wrong fix (hacky – don’t do this)
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function addItem() { items.value.push('Cherry') this.$forceUpdate() // ← forces re-render } |
Correct fix (Vue way – 2026 style)
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function addItem() { // Option A: mutate the ref's value (Vue detects) items.value.push('Cherry') // Option B: create new array (also detected) items.value = [...items.value, 'Cherry'] } |
→ Vue’s reactivity system sees the array change → automatic re-render
4. Another Classic Case – Replacing Reactive Object
Buggy code
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<script setup> import { reactive } from 'vue' const state = reactive({ count: 0 }) function reset() { // WRONG: replacing the reactive proxy breaks reactivity! state = { count: 0 } // ← reactivity lost forever } </script> |
→ After reset → changing state.count no longer updates UI
Wrong fix
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function reset() { state = { count: 0 } getCurrentInstance().proxy.$forceUpdate() // hack } |
Correct fixes (choose one)
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// Option 1: mutate existing object function reset() { state.count = 0 } // Option 2: use ref instead of reactive if you need to replace const state = ref({ count: 0 }) function reset() { state.value = { count: 0 } // ref allows replacement } |
5. When $forceUpdate() Is Actually Legitimate (Very Rare in 2026)
There are very few legitimate cases:
- Third-party non-reactive library mutated internal state Example: some old jQuery plugin changed DOM directly → Vue doesn’t know → force update
- Direct DOM mutation that Vue cannot track Example: document.getElementById(‘myId’).innerHTML = ‘new’ → Vue misses it
- Legacy bridge code (integrating Vue 2 plugin into Vue 3)
- Debugging / temporary workaround while you fix the real reactivity issue
But even in these cases → better solutions usually exist:
- Use nextTick() + ref to wait for DOM
- Wrap third-party lib in a reactive wrapper
- Use markRaw + manual reactivity
- Rewrite the integration properly
6. Quick Summary Table – $forceUpdate() Reality Check (2026)
| Question | Answer / Reality in 2026 |
|---|---|
| Do modern Vue 3 developers use it? | Almost never — it’s a code smell |
| When do you see it? | Legacy Options API code, old tutorials, quick hacks |
| Does it fix reactivity bugs? | No — it only hides them temporarily |
| Does it re-run lifecycle / setup? | No — only forces render + patch |
| Better alternatives | Fix reactivity (use ref/reactive properly), nextTick, emit events |
| Seen in Devtools / docs? | Yes — but mostly for Options API & debugging |
Final 2026 Advice from Real Projects
- In new code → you should never need$forceUpdate()
- If you feel like you need it → you almost certainly have a reactivity bug — fix the root cause
- When you see $forceUpdate() in code → treat it as a warning sign:
- Someone didn’t understand reactivity
- It’s legacy code
- It’s a temporary hack that should be refactored
- Preferred modern solutions:
- Use ref / reactive correctly
- Use nextTick() when DOM timing matters
- Emit events upward instead of reaching to parent/root
- Use Pinia / provide-inject for shared state
- Wrap third-party libs properly with reactivity
Your mini homework:
- Create the buggy counter example (push on plain array)
- Add $forceUpdate() → see it “works” but feels wrong
- Refactor properly with items.value.push() → see the clean Vue way
- Try replacing reactive object → see reactivity break → fix with ref
Any part confusing? Want to see:
- Full Options API vs Composition API reactivity comparison?
- Real third-party library integration that tempts people to use $forceUpdate()?
- Common reactivity bugs and their proper fixes?
- When $forceUpdate() is actually used in production (very rare cases)?
Just tell me — we’ll debug and fix reactivity together step by step 🚀
