194897 2019-02-21 06:22:40 -0800 navigator.sendBeacon does not work on visibilitychange callback for document unload 2022-07-05 14:11:51 -0700 1 1 1 Unclassified WebKit WebCore Misc. Safari Technology Preview Mac macOS 10.14 RESOLVED DUPLICATE 151234 https://bugs.webkit.org/show_bug.cgi?id=116769 https://bugs.webkit.org/show_bug.cgi?id=151234 https://bugs.webkit.org/show_bug.cgi?id=151610 InRadar P2 Normal --- 1 bastien.caudan webkit-unassigned cdumez code mike webkit-bug-importer webkit oldest_to_newest 1508500 0 bastien.caudan 2019-02-21 06:22:40 -0800 With the example from the beacon spec (https://w3c.github.io/beacon/): document.addEventListener('visibilitychange', function() { if (document.visibilityState === 'hidden') { navigator.sendBeacon('/collector', data); } }); From manual tests on hidden cases, navigator.sendBeacon is triggered correctly when: - the browser is minimized. - the document is not the active tab But navigator.sendBeacon is not triggered when: - the browser unload the document Other browsers that support the Beacon API allow these requests to be sent. 1508868 1 webkit-bug-importer 2019-02-21 20:49:37 -0800 <rdar://problem/48301429> 1546983 2 code 2019-06-21 14:08:29 -0700 The visibilitychange event don’t fire at all during unload. This is a duplicate of issue #116769. 1691793 3 mike 2020-09-24 23:33:46 -0700 See the https://volument.com/blog/sendbeacon-is-broken#comments comments discussion for some real-world pain points developers are hitting due to this. (So that not only do we need to make developers aware that they shouldn’t be trying to use unload/onunload with sendBeacon(), and that they instead need to visibilitychange — but *also* need to check pagehide (because we don’t yet have visibilitychange working interoperably for them across the web platform). 1880799 4 gsnedders 2022-07-05 14:11:51 -0700 *** This bug has been marked as a duplicate of bug 151234 ***