[Announcement] Deprecating the unload event

[nishitha-burman]

The Google Chrome team plans to deprecate the unload event starting in Chrome version 117. The deprecation is done by gradually changing the default so unload handlers stop firing on pages unless a page explicitly opts in to re-enable them. For more information, see Deprecating the unload event - Chrome Developers, and Google Groups - Conversations.

While we haven't yet finalized the deprecation schedule, we anticipate that Microsoft Edge follows Chrome's schedule with a possible delay of a release or two. This will have a cascading effect in Microsoft Edge WebView2. If you're interested in testing with version 118, the ForcePermissionPolicyUnloadDefaultEnabled policy is available or you can use the instructions documented at Disable unload handlers by default and add Permissions-Policy to opt-in to enabling them. WebView2 will support both the permissions policy and the enterprise policy but won't be impacted by the gradual rollout in Microsoft Edge. We expect WebView2 will switch defaults when the roll out reaches 100% of page loads.