Only automatically update when page not being viewed

views/index.html

@@ -450,8 +450,19 @@
               }
             };
 
+            let inView = true;
+            window.onfocus = window.onblur = window.onpageshow = window.onpagehide = function (e) {
+              if ({focus:1, pageshow:1}[e.type]) {
+                if (inView) return;
+                inView = true;
+              } else if (inView) {
+                inView = false;
+              }
+            };
+
             // Fetch updates every 5 minutes
             setInterval(() => {
+              if (!inView) {
                 fetch(`/api/unread`)
                   .then(res => res.json())
                   .then(items => {
@@ -470,7 +481,8 @@
                     }
 
                     this.setPageTitle();
-                })
+                  });
+              }
             }, 5 * 60 * 1000);
 
             document.addEventListener('keydown', this._keyListener.bind(this));