Browser Cache API

cache.js

// Source: https://blog.logrocket.com/beyond-cookies-todays-options-for-client-side-data-storage/

const apiRequest = new Request('https://www.example.com/items');
caches.open('exampleCache') // opens the cache
  .then(cache => {
    cache.match(apiRequest) // checks if the request is cached
      .then(cachedResponse => 
        cachedResponse || // return cachedReponse if available
        fetch(apiRequest) // otherwise, make new request
          .then(response => {
            cache.put(apiRequest, response); // cache the response
            return response;
          })
        })
    .then(res => console.log(res))
})