According to HTML5 spec persisted user state (scroll, scale, form values, etc) should be restored before dispatching popstate event. (See steps 9 and 14 in history traversal algorithm[1]).
Gecko and IE follow the spec order for scroll position but in Blink and WebKit the order is reversed specifically: 1. 'popstate' event dispatched 2. scroll position restored (only if user has not scrolled) 3. 'hashchanged' event dispatched (only if hash changed) We have learned that single-page applications depend on this reverse order to implement a simple workaround to override automatic scroll position restoration with their own application specific one. The workaround is to record the scroll position on (1), and restore it on (3). In fact, a recent change in the Blink's order [2] broke major sites that depended on this reverse order and we had to revert it. At the same time, this means that the scroll restoration for any sites that uses this workaround does not work well in Firefox and IE. I have heard examples of this from Mozilla engineers. There are two options to get an interop solution: Option 1. Change the spec to reverse order, making the workaround supported officially. Does anybody know if there was any specific reasons behind the current order? Option 2. Keep the spec order, and have Blink and Webkit match it. This depends on having a reliable methods for controlling scroll restoration so that current workaround users can switch to it. Fortunately history.scrollRestoration [3, 4] provides exactly this alternative and we are working toward shipping it in blink in the next release [5]. I prefer option 2 mainly because the current order has the advantage that when 'popstate' is dispatched the application is guaranteed that the user-agent is done with restoring the state, and current values are reliable. Furthermore, the workaround has multiple other limitations: - scroll position needs to be restored synchronously otherwise a jump is visible - requires apps to create artificial hashchange events Have I missed any other solution? Majid [1] https://html.spec.whatwg.org/multipage/browsers.html#traverse-the-history [2] https://crbug.com/474579 [3] https://lists.w3.org/Archives/Public/public-whatwg-archive/2015May/0063.html [4] https://html.spec.whatwg.org/multipage/browsers.html#traverse-the-history [5] https://crbug.com/444094