---
title: "rerender memo"
description: "Extract expensive work into memoized components to enable early returns before computation."
type: skill
canonical_url: https://claudary.paisolsolutions.com/skills/rerender-memo
source: "Claudary"
difficulty: intermediate
author: "Claude Code Knowledge Pack"
date: 2026-07-10T11:46:04.709Z
license: CC-BY-4.0
attribution: "rerender memo — Claudary (https://claudary.paisolsolutions.com/skills/rerender-memo)"
---

# rerender memo
Extract expensive work into memoized components to enable early returns before computation.

## Overview

---
title: Extract to Memoized Components
impact: MEDIUM
impactDescription: enables early returns
tags: rerender, memo, useMemo, optimization
---

## Extract to Memoized Components

Extract expensive work into memoized components to enable early returns before computation.

**Incorrect (computes avatar even when loading):**

```tsx
function Profile({ user, loading }: Props) {
  const avatar = useMemo(() => {
    const id = computeAvatarId(user)
    return <Avatar id={id} />
  }, [user])

  if (loading) return <Skeleton />
  return <div>{avatar}</div>
}
```

**Correct (skips computation when loading):**

```tsx
const UserAvatar = memo(function UserAvatar({ user }: { user: User }) {
  const id = useMemo(() => computeAvatarId(user), [user])
  return <Avatar id={id} />
})

function Profile({ user, loading }: Props) {
  if (loading) return <Skeleton />
  return (
    <div>
      <UserAvatar user={user} />
    </div>
  )
}
```

**Note:** If your project has [React Compiler](https://react.dev/learn/react-compiler) enabled, manual memoization with `memo()` and `useMemo()` is not necessary. The compiler automatically optimizes re-renders.

---

Source: [Claudary](https://claudary.paisolsolutions.com/skills/rerender-memo) · https://claudary.paisolsolutions.com