This feature allows pages to disable the running of unload event handlers. The goal is to : - allow sites that have removed all unload handlers to ensure they do not accidentally add new ones - allow sites to remove unload handlers when updating the code would is infeasible Unload event handlers are problematic for various reasons and prevent use of BFCache on Desktop (see https://web.dev/bfcache/#never-use-the-unload-event).

Motivation

Help sites migrate off unload event handlers and thereby improve BFCache hit-rate: - by ensuring that once removed, handlers do not creep back in - by providing a means to disable handlers in 3rd party iframes and script that is hard to change

Specification

Specification link


Proposal in a personal repository, no adoption from community

Status in Chromium

Blink>PermissionsAPI


No active development (tracking bug)

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • Negative
  • No signal
  • Positive

Owner

Intent to Prototype url

Intent to Prototype thread

Last updated on 2022-05-13