diff --git a/templates/index.html b/templates/index.html
index 8f85f08..a45e14b 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -1,6 +1,15 @@
 <!DOCTYPE html>
 <html lang="en">
 <head>
+    <!-- Google tag (gtag.js) -->
+    <script async src="https://www.googletagmanager.com/gtag/js?id=G-HJ9JZT892E"></script>
+    <script>
+      window.dataLayer = window.dataLayer || [];
+      function gtag(){dataLayer.push(arguments);}
+      gtag('js', new Date());
+
+      gtag('config', 'G-HJ9JZT892E');
+    </script>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Janus: Bayesian A/B Testing App</title>
