PopStateEvent

History history

Baseline: Widely available on the web, in every major browser since Jul 2015, and long enough to count on (since Jan 2018).

niso: Partial 18%. 55 of 304 subtests pass, by system: Linux 18%, macOS 18%. Engines: QuickJS, the engine niso's WPT run uses; Node and Porffor have no recorded run. WPT results recorded at f3b4fa8, 2026-11-10; web-features 3.45.0. WPT tests · niso's support · History, PopStateEvent, Window

PopStateEvent is an interface in idl/html.webidl, inheriting Event, exposed in Window. What it does is on MDN; this page says what niso has of it.

The standard’s constructors, which take dictionaries with any and string members, are not supported yet.

Status

The web features its members belong to, each with its Baseline status on the web and how much of the feature’s WPT suite passes in niso (see Web platform support).

Feature	On the web	In niso	Members
History	Widely available	Partial 18% 55 of 304 subtests pass	3

Members

state

attribute

readonly attribute any state;

int32_t niso_pop_state_event_get_state(niso_dom* dom, niso_handle self, niso_bytes* out);

hasUAVisualTransition

attribute

readonly attribute boolean hasUAVisualTransition;

int32_t niso_pop_state_event_get_has_ua_visual_transition(niso_dom* dom, niso_handle self, bool* out);

Not in niso yet

Members the web has, by the BCD keys web-features 3.45.0 lists, that idl/ doesn’t declare. The list is partial: web-features lists only the keys it maps to a feature.

• PopStateEvent (History)