A few years back I wrote a blog post about how write a fetch Promise that times out. The function was effective but the code wasn’t great, mostly because AbortController , which allows you to cancel a fetch Promise, did not yet exist. With AbortController and AbortSignal available, let’s create a better JavaScript function for fetching with a timeout:

Much like the original function, we’ll use setTimeout to time to the cancellation but we’ll use the signal with the fetch request:

async function fetchWithTimeout(url, opts = {}, timeout = 5000) {   // Create the AbortController instance, get AbortSignal   const abortController = new AbortController();   const { signal } = abortController;    // Make the fetch request   const _fetchPromise = fetch(url, {     ...opts,     signal,   });    // Start the timer   const timer = setTimeout(() => abortController.abort(), timeout);    // Await the fetch with a catch in case it's aborted which signals an error   try {     const result = await _fetchPromise;     clearTimeout(timer);     return result;   } catch (e) {     clearTimeout(timer);     throw e;   } };  // Usage try {   const impatientFetch = await fetchWithTimeout('/', {}, 2000); } catch(e) {   console.log("fetch possibly canceled!", e); } 

The JavaScript code above is much cleaner now that we have a proper API to cancel fetch Promise calls. Attaching the signal to the fetch request allows us to use a setTimeout with abort to cancel the request after a given amount of time.

It’s been excellent seeing AbortController, AbortSignal, and fetch evolve to make async requests more controllable without drastically changing the API.

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