React Query vs. SWR vs. Zustand: picking the right state tool

Client vs Server State

One of the biggest sources of complexity in React applications is mixing server-side state (fetched databases, user sessions) with client-side state (sidebar toggles, modal indicators, current form fields).

The React Query paradigm

React Query (or SWR) handles caching, polling, deduplication, and loading/error states for server data, leaving client state management tools like Zustand or Context to handle local UI variables.

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

function UserProfile() {
  const { data, isLoading, error } = useQuery({
    queryKey: ['userProfile'],
    queryFn: fetchUserProfile
  })

  if (isLoading) return <div>Loading profile...</div>
  if (error) return <div>Error fetching data</div>

  return <div>Welcome back, {data.name}</div>
}