Smart Prefetching with TanStack Query for Instant UX

Prefetching data is one of the most powerful techniques in React Query. It helps you improve perceived performance by loading data before the user needs it — resulting in near-instant navigation.

In this guide, you’ll learn how to:

• Use queryClient.prefetchQuery
• Prefetch on hover or intent
• Handle error cases
• Combine it with useQuery for cache re-use

Let’s explore the cleanest and most efficient way to prefetch in React apps using TanStack Query.

🧠 What is Prefetching?

Prefetching means fetching and caching data ahead of time, before the component that uses it is mounted.

You might trigger it when:

• The user hovers a link
• The user is likely to navigate soon
• You want to warm the cache at app load

🛠 Basic Example Using prefetchQuery

      import { useQuery, useQueryClient } from '@tanstack/react-query';

const fetchPost = async (id: number) => {
  const res = await fetch(`/api/posts/${id}`);
  if (!res.ok) throw new Error('Post fetch failed');
  return res.json();
};

export default function PostLink({ id }: { id: number }) {
  const queryClient = useQueryClient();

  return (
    <a
      href={`/posts/${id}`}
      onMouseEnter={() => {
        queryClient.prefetchQuery(['post', id], () => fetchPost(id));
      }}
    >
      View Post #{id}
    </a>
  );
}
    

This example will prefetch the post data when the user hovers the link.

❗ Handling Errors in prefetchQuery

Because prefetchQuery is fire-and-forget by default, it won’t throw on error unless you await it:

      try {
  await queryClient.prefetchQuery(['post', id], () => fetchPost(id));
} catch (err) {
  console.error('Prefetch failed:', err);
}
    

If you want error handling (e.g. logging, fallback), always await the result. This is especially useful in useEffect, SSR, or proactive preloading.

🔄 How it Works with useQuery

When the user navigates to the post page:

      const { data } = useQuery(['post', id], () => fetchPost(id));
    

React Query will first check the cache — and instantly return the prefetched result.

No loading spinner. No delay. Just speed.

📦 Prefetching in useEffect (on page load)

You can also prefetch on mount:

      useEffect(() => {
  queryClient.prefetchQuery(['settings'], fetchSettings);
}, []);
    

Useful for dashboards, config pages, or background tasks.

🤝 Combine with ensureQueryData

TanStack Query 5+ provides ensureQueryData, which will fetch or return cached:

      await queryClient.ensureQueryData({
  queryKey: ['user'],
  queryFn: () => fetchUser(),
});
    

This is useful for layout-level data (e.g. user auth or settings).

✅ Summary

Prefetching in React Query isn’t just a trick — it’s a UX superpower. Use it to deliver blazing-fast transitions and real-time feeling apps without loading spinners.