diff --git a/_includes/cookie-consent.html b/_includes/cookie-consent.html
index 8a0f5c6..03f5578 100644
--- a/_includes/cookie-consent.html
+++ b/_includes/cookie-consent.html
@@ -31,14 +31,16 @@
         createCookie(name,"",-1);
     }
 
-    function load_google_analytics() {
-      window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
-      ga('create', 'UA-44071631-2', 'auto');
-      ga('send', 'pageview');
+    function load_google_analytics_tag_manager() {
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+
+      gtag('config', 'G-2YX2GXC6Q8');
     }
 
     if(readCookie('cookie-notice-dismissed')=='accepted') {
-      load_google_analytics()
+      load_google_analytics_tag_manager()
     } else if(readCookie('cookie-notice-dismissed')=='rejected') {
       // do nothing
     } else  {
@@ -48,7 +50,7 @@
     document.getElementById('cookie-notice-accept').addEventListener("click",function() {
         createCookie('cookie-notice-dismissed','accepted',31);
         document.getElementById('cookie-notice').style.display = 'none';
-        load_google_analytics()
+        load_google_analytics_tag_manager()
     });
 
     document.getElementById('cookie-notice-reject').addEventListener("click",function() {
diff --git a/_layouts/default.html b/_layouts/default.html
index 2e436a9..d4d0a60 100644
--- a/_layouts/default.html
+++ b/_layouts/default.html
@@ -4,12 +4,16 @@
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
 
+    <!-- Google tag (gtag.js) (old Google analytics) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-2YX2GXC6Q8"></script>
+    <!-- comment out below and uncomment "include cookie-consent.html" below -->
     <script>
-      window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
-      ga('create', 'UA-44071631-2', 'auto');
-      ga('send', 'pageview');
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+
+      gtag('config', 'G-2YX2GXC6Q8');
     </script>
-    <script async src='https://www.google-analytics.com/analytics.js'></script>
 
     {% if page.url == "/" %}<title>{{ site.description }}</title>{% else %}<title>{{ page.title | default: site.title }}</title>{% endif %}
 
diff --git a/tools/recursion-visualization/index.html b/tools/recursion-visualization/index.html
index fec4595..394fd26 100644
--- a/tools/recursion-visualization/index.html
+++ b/tools/recursion-visualization/index.html
@@ -11,12 +11,15 @@
     <link rel="manifest" href="/icon/site.webmanifest">
     <link rel="mask-icon" href="/icon/safari-pinned-tab.svg" color="#5bbad5"><link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&display=swap">
 
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-2YX2GXC6Q8"></script>
     <script>
-      window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date;
-      ga('create', 'UA-44071631-2', 'auto');
-      ga('send', 'pageview');
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+
+      gtag('config', 'G-2YX2GXC6Q8');
     </script>
-    <script async src='https://www.google-analytics.com/analytics.js'></script>
 
     <script data-ad-client="ca-pub-2026571203025921" async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
 </head>