jQuery Forum

Defining fallback transitions for non-3D support

By default, all transitions except fade require 3D transform support. Devices that lack 3D support will fall back to a fade transition, regardless of the transition specified. We do this to proactively exclude poorly-performing platforms like Android 2.x from advanced transitions and ensure they still have a smooth experience. Note that there are platforms such as Android 3.0 that technically support 3D transforms, but still have poor animation performance so this won't guarantee that every browser will be 100% flicker-free but we try to target this responsibly.

The fallback transition for browsers that don't support 3D transforms can be configured for each transition type, but by default we specify "fade" as the fallback. For example, this will set the fallback transition for the slideout transition to "none":

$.mobile.fallbackTransition.slideout = "none"

Unfortunately, after a ton of work, we’ve determined that it’s not possible to dumb down page transitions enough to get acceptable performance in Android 2.x, even on a newer device like a Nexus S running 2.3. After a lot of deliberation, we’ve decided to use a feature test for 3D transforms to target transitions: if a browser passes, it will see the full range of transitions. By default, if a browser fails this 3D test, they will fall back to a fade transition, regardless of the transition specified. All Android 1.x-2.x devices fail this test but Android 3.x and 4.x pass. The fallback behavior for each transition is completely configurable if you want to change this behavior.

TL;DR: The default page transition is now be a super fast and smooth fade out/in animation. All the 1.1 page transitions (slide, flip, etc.)  have been tweaked to have a place it the animation where we fade out to accomodate the scroll jump, but we think this looks pretty sharp and always in control. On some platforms like Android 2.x that don’t support 3D effects, the simpler fade transition will be the only game in town, regardless of the transition specified.