The precommitHandler callback option to NavigateEvent's intercept() method returns a promise that defers navigation until the promise resolves. You can use this to change the navigation's URL, state, and history before navigation occurs. Shipping in Safari 27.3 (beta). Probes NavigationPrecommitController. More: developer.mozilla.org/docs/Web/API/NavigationPreco… html.spec.whatwg.org/multipage/nav-history-apis.ht… web-platform-dx.github.io/web-features-explorer/fe…
typeof NavigationPrecommitController !== "undefined"typeof NavigationPrecommitController !== "undefined"