See https://github.com/w3c/web-platform-tests/pull/5553#issuecomment-310052695 /html/browsers/the-window-object/apis-for-creating-and-navigating-browsing-contexts-by-name/open-features-tokenization-innerheight-innerwidth.html "innerwidth=401" should set width of opened window FAIL: 3/10, PASS: 7/10 assert_equals: expected 401 but got 800 etc. I could not reproduce with either Safari 10.1.1 (12603.2.4) stable or Safari TP (Release 33 (Safari 11.0, WebKit 12604.1.25.0.2)) with that test locally. (The test requires the popup-blocker to be disabled.)