(opening this as a separate issue from https://bugs.webkit.org/show_bug.cgi?id=122212) Chrome [1], Firefox and MS Edge currently remove the 300-350ms delay between touchend and the mouse compatibility events (see [2]) for "mobile optimized" pages that have a viewport of width=device-width. Pages are still zoomable using pinch-to-zoom, but not double-tap-to-zoom. Supporting this in iOS would obviate the need for mobile sites to use tricks such as fastclick.js Although a more declarative method will now be available with touch-action:manipulation [3], it may still be worth considering this for compatibility with the other major browsers (and the fact that it's arguably the path of least resistance for developers: support for this would mean that sites which currently use width=device-width and fastclick.js can simply remove the latter, vs removing fastclick AND explicitly adding touch-action:manipulation). [1] https://developers.google.com/web/updates/2013/12/300ms-tap-delay-gone-away?hl=en [2] http://patrickhlauke.github.io/touch/tests/results/#suppressing-300ms-delay [3] https://bugs.webkit.org/show_bug.cgi?id=149854
Copying over a useful comment from rbyers from https://bugs.webkit.org/show_bug.cgi?id=122212 which provides some hard data "Some usage data from Chrome which may be helpful in having a data-oriented debate here: - only 0.6% of taps lead to a double tap - rises to 3.5% considering only sites where double tap is enabled - 75% (and increasing) of pages loaded on Android have a mobile viewport - 84% of taps (and increasing) occur on pages with a mobile viewport"
*** This bug has been marked as a duplicate of bug 150604 ***