Why does fetch not enter catch when the server returns HTTP 404 or 500?

A completed HTTP response can resolve the fetch promise even when its status indicates failure. Check response.ok.

async function loadQuestions(signal) {
  const response = await fetch("/api/questions", { signal });
  if (!response.ok) {
    throw new Error(`Request failed: HTTP ${response.status}`);
  }
  return await response.json();
}

Network failures, cancellation, and invalid JSON can also throw. Handle these in the caller and display a useful retry state. If an endpoint returns 204 No Content, do not call json() for that response. Parse documented error payloads separately and avoid exposing raw server responses in the UI.

Reference: MDN Fetch guide.

AI-assisted DevCircle editorial explanation. Corrections and alternative solutions are welcome.