React Diagnostic

Fix "Hydration failed because the initial UI does not match what was rendered on the server"

Occurs in SSR frameworks like Next.js or Remix when server-rendered HTML markup differs from client-side initial render output (due to timestamps, window/localStorage checks, or invalid HTML nesting).

Hydration failed because the initial UI does not match

Quick Fix Checklist

  1. Defer client-only state updates until after useEffect has run
  2. Use dynamic(() => Component, { ssr: false }) for purely client components
  3. Add suppressHydrationWarning to element nodes rendering inevitable variations (e.g. formatted local dates)
  4. Inspect DOM tree for invalid HTML nesting like <p> tags enclosing <div> tags or <table> without <tbody>