The Event Horizon

Common Pitfalls.

Next.js is powerful, but easy to break. We've mapped the most common "Black Holes" so you can diagnose and fix them instantly.

The server-rendered HTML doesn't match the client-rendered output (e.g., using new Date() or Math.random()).

Attempting to use browser-only hooks like 'useState' or 'useEffect' inside a Server Component.

Trying to pass functions, classes, or private symbols through the Server-to-Client boundary.

Using a dynamic function (like headers() or cookies()) in a page that is being pre-rendered statically.

Accessing 'params' or 'searchParams' synchronously in a Page or Layout without awaiting them.