title: Long time waiting Request to Service Worker
body: <p>I have noticed that the time waiting for service workers to respond with items from the cache is not as fast as you would expect it to be. I have seen the same wait times with both <code>sw-precache</code> and a custom written service worker.</p>
  
  <p><a href="https://i.stack.imgur.com/9cBsR.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9cBsR.png" alt="Request to ServiceWorker"></a></p>
  
  <p>What are the possible causes for this wait time time and how could I reduce it?</p>
  
  <p>My <code>fetch</code> event on the custom service worker looks like:</p>
  
  <pre><code>self.addEventListener('fetch', function(event) {
      event.respondWith(
          caches.match(event.request).then(function(response) {
              if (response) {
                  return response;
              }
              return fetch(event.request);
          })
      );
  });
  </code></pre>