TIL: AbortSignal.timeout() — Add Fetch Timeouts in One Line

TIL that AbortSignal.timeout(ms) exists — and it replaces about eight lines of AbortController boilerplate with one.

The Old Way

Adding a timeout to fetch used to require a controller, a timer, and a cleanup step:

const controller = new AbortController();
const timerId = setTimeout(() => controller.abort(), 5000);

try {
  const res = await fetch(url, { signal: controller.signal });
  const data = await res.json();
  return data;
} finally {
  clearTimeout(timerId); // easy to forget
}

If you skip the clearTimeout, the timer keeps the event loop alive and can fire after the response is already processed.

The New Way

AbortSignal.timeout(ms) returns a signal that aborts itself after the given number of milliseconds — no controller, no timer variable, no cleanup:

const res = await fetch(url, { signal: AbortSignal.timeout(5000) });
const data = await res.json();
return data;

That's it. When the timeout fires, fetch throws a DOMException with name === 'TimeoutError', which you can catch specifically:

try {
  const res = await fetch(url, { signal: AbortSignal.timeout(5000) });
  return await res.json();
} catch (err) {
  if (err.name === 'TimeoutError') {
    throw new Error('Request timed out after 5 s');
  }
  throw err; // AbortError, TypeError, network errors, etc.
}

Combining a Timeout with Manual Cancellation

If you need both — a timeout and the ability to cancel manually — use AbortSignal.any() (Node 20.3+, Chrome 116+):

const controller = new AbortController();

const signal = AbortSignal.any([
  controller.signal,         // manual cancel
  AbortSignal.timeout(5000), // auto timeout
]);

const res = await fetch(url, { signal });

// elsewhere, to cancel early:
controller.abort();

The combined signal aborts as soon as either source fires.

Browser and Node Support

| Environment | Since | |---|---| | Chrome | 103 | | Firefox | 100 | | Safari | 16 | | Node.js | 17.3 | | Deno | 1.23 |

All modern runtimes support it. If you need to target older Node.js (< 17.3), fall back to the manual AbortController approach.

The Practical Upside

The old pattern had two failure modes: forgetting clearTimeout (leaks a timer) and forgetting to pass the signal (the controller does nothing). AbortSignal.timeout removes both. The timeout is attached directly to the signal, so there is nothing to clean up and nothing to forget to wire in.