Policy
Control the behavior for the cancel dialog produced by the beforeunload event (obsolete)
Microsoft Edge
Policy overview
Key metadata and intent for this policy.
Supported OS tags: Windows7
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 130. This policy provides a temporary opt-out for two related fixes to the behavior of the confirmation dialog that’s shown by the beforeunload event. If you've enabled this policy, the new (correct) behavior is used. If you've disabled this policy, the old (legacy) behavior is used. If you haven't configured this policy, the default behavior is used. Note: This policy is a temporary workaround and is going to be removed in a future release. New and correct behavior: In `beforeunload`, calling `event.preventDefault()` triggers the confirmation dialog. Setting `event.returnValue` to the empty string doesn’t trigger the confirmation dialog. Old and legacy behavior: In `beforeunload`, calling `event.preventDefault()` doesn’t trigger the confirmation dialog. Setting `event.returnValue` to the empty string triggers the confirmation dialog.
Registry values
How enabled and disabled states update the registry.
| Scope | Registry location | Type | Enabled value | Disabled value | Copy |
|---|---|---|---|---|---|
Path Software\Policies\Microsoft\Edge Value name BeforeunloadEventCancelByPreventDefaultEnabled | REG_DWORD | HKLM 1 HKCU 1 | HKLM 0 HKCU 0 |
Policy elements
Inputs and configuration options exposed by this policy.
This policy has no additional user input fields.