diff --git a/docs/index.html b/docs/index.html
index bbcbbabc..79028c98 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -42,6 +42,9 @@
       mergeNavbar: true,
       formatUpdated: '{YYYY}-{MM}-{DD} {HH}:{mm}:{ss}',
     }
+    if (typeof navigator.serviceWorker !== 'undefined') {
+        navigator.serviceWorker.register('serviceWorker.js')
+    }
   </script>
   <script src="https://cdn.bootcss.com/docsify/4.5.5/docsify.min.js"></script>
 </body>
diff --git a/docs/serviceWorker.js b/docs/serviceWorker.js
new file mode 100644
index 00000000..34634e1e
--- /dev/null
+++ b/docs/serviceWorker.js
@@ -0,0 +1,75 @@
+const RUNTIME = 'docsify'
+const HOSTNAME_WHITELIST = [
+    self.location.hostname,
+    'fonts.gstatic.com',
+    'fonts.googleapis.com',
+    'cdn.bootcss.com'
+]
+
+// The Util Function to hack URLs of intercepted requests
+const getFixedUrl = (req) => {
+    var now = Date.now()
+    var url = new URL(req.url)
+
+    // 1. fixed http URL
+    // Just keep syncing with location.protocol
+    // fetch(httpURL) belongs to active mixed content.
+    // And fetch(httpRequest) is not supported yet.
+    url.protocol = self.location.protocol
+
+    // 2. add query for caching-busting.
+    // Github Pages served with Cache-Control: max-age=600
+    // max-age on mutable content is error-prone, with SW life of bugs can even extend.
+    // Until cache mode of Fetch API landed, we have to workaround cache-busting with query string.
+    // Cache-Control-Bug: https://bugs.chromium.org/p/chromium/issues/detail?id=453190
+    if (url.hostname === self.location.hostname) {
+        url.search += (url.search ? '&' : '?') + 'cache-bust=' + now
+    }
+    return url.href
+}
+
+/**
+ *  @Lifecycle Activate
+ *  New one activated when old isnt being used.
+ *
+ *  waitUntil(): activating ====> activated
+ */
+self.addEventListener('activate', event => {
+    event.waitUntil(self.clients.claim())
+})
+
+/**
+ *  @Functional Fetch
+ *  All network requests are being intercepted here.
+ *
+ *  void respondWith(Promise<Response> r)
+ */
+self.addEventListener('fetch', event => {
+    // Skip some of cross-origin requests, like those for Google Analytics.
+    if (HOSTNAME_WHITELIST.indexOf(new URL(event.request.url).hostname) > -1) {
+    // Stale-while-revalidate
+    // similar to HTTP's stale-while-revalidate: https://www.mnot.net/blog/2007/12/12/stale
+    // Upgrade from Jake's to Surma's: https://gist.github.com/surma/eb441223daaedf880801ad80006389f1
+    const cached = caches.match(event.request)
+    const fixedUrl = getFixedUrl(event.request)
+    const fetched = fetch(fixedUrl, { cache: 'no-store' })
+    const fetchedCopy = fetched.then(resp => resp.clone())
+
+    // Call respondWith() with whatever we get first.
+    // If the fetch fails (e.g disconnected), wait for the cache.
+    // If there’s nothing in cache, wait for the fetch.
+    // If neither yields a response, return offline pages.
+    event.respondWith(
+        Promise.race([fetched.catch(_ => cached), cached])
+.then(resp => resp || fetched)
+.catch(_ => { /* eat any errors */ })
+)
+
+    // Update the cache with the version we fetched (only for ok status)
+    event.waitUntil(
+        Promise.all([fetchedCopy, caches.open(RUNTIME)])
+            .then(([response, cache]) => response.ok && cache.put(event.request, response))
+        .catch(_ => { /* eat any errors */ })
+)
+}
+})
\ No newline at end of file