From 0577cba1bfd1ce45af8676f5c24fb8459176703e Mon Sep 17 00:00:00 2001
From: Raju Ahmed <raju.ahmed@optimizely.com>
Date: Thu, 9 Oct 2025 16:16:27 +0600
Subject: [PATCH] [FSSDK-11879] use visibilitychange event for page hide
 detection

---
 lib/index.browser.ts | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/index.browser.ts b/lib/index.browser.ts
index 0f644a844..ffa291f33 100644
--- a/lib/index.browser.ts
+++ b/lib/index.browser.ts
@@ -33,13 +33,18 @@ export const createInstance = function(config: Config): Client {
   });
 
   if (client) {
-    const unloadEvent = 'onpagehide' in window ? 'pagehide' : 'unload';
-    window.addEventListener(
-      unloadEvent,
-      () => {
+    if ('onvisibilitychange' in document) {
+      document.addEventListener('visibilitychange', () => {
+        if (document.hidden) {
+          client.flushImmediately();
+        }
+      });
+    } else {
+      const unloadEvent = 'onpagehide' in window ? 'pagehide' : 'unload';
+      window.addEventListener(unloadEvent, () => {
         client.flushImmediately();
-      },
-    );
+      });
+    }
   }
 
   return client;