404 Error (Not Found)

A 404 error is the web's way of saying "this page doesn't exist." When a user visits a URL that has no matching route or the resource has been deleted, the server responds with HTTP status code 404. It is one of the most common errors on the web.

HTTP status codes are grouped by category: 2xx means success (200 OK), 3xx means redirect (301 Moved), 4xx means client error (404 Not Found, 401 Unauthorized, 403 Forbidden), and 5xx means server error (500 Internal Server Error). Knowing these codes helps you debug issues quickly.

For vibe coders, handling 404s gracefully is part of good UX. Next.js provides a not-found.tsx file where you can design a custom 404 page. AI tools can generate these pages, but the UX decision of what to show (helpful links, search bar, humor) is still yours.