When the "requireInteraction" option is set to true, a persistent notification should be shown. This seems not to happen on Linux with the libnotify backend. https://bugzilla.mozilla.org/show_bug.cgi?id=862395#c26 wrote some suggestions for implementation, but it seems that nobody ever followed up on that, and requireInteraction is only supported for XUL notifications. STR: 1. Visit about:config and ensure that dom.webnotifications.requireinteraction.enabled is true. 2. Run the following snippet, e.g. from the devtools in a tab: Notification.requestPermission().then(function() { new Notification('hello', {requireInteraction:true}); }); Expected: - A notification shows up that sticks around. Actual: - The notification disappears after 5 seconds. This 5 seconds delay seems to be the default for my system. If I open a terminal and run the following commands, then I can see that the notification disappears at the expected times: $ notify-send hello # gone in 5 seconds (default). $ notify-send -t 1000 hello # gone in 1 second. $ notify-send -t 9000 hello # gone in 9 seconds.

It seems like this should be fixed (as much as platform support allows; see bug 862395 comment 26) so we aren't shipping a half-baked platform feature.