KTween - the world's fastest simple tween engine for AS3

I've released the quite new, simple, lightweight tween engine for ActionScript 3.0. This would come to be the best choice for developing mobile contents targeting smart phones. Currently, at the moment of the mid-February, the KTween is the world's fastest tween engine for the lightweight AS3 web development scene. This open source product is available on the Google Code under the MIT license.

18.9% faster than the Tweener

The benchmark tweens 2,000 objects in six seconds. I run it three times for each tween engines to take the average frame-rate below.
I run this on the standalone Flash Player, Core 2 Duo 2.26 GHz, MacBook Pro Unibody. The screen capture is:
Larger number of fps means faster. Source code of this is here.

KTween27.19 fps
BetweenAS326.77 fps
TweenNano26.70 fps
GTween26.38 fps
Tweener22.87 fps

Note that the KTween engine is one of the most reasonable alternative for the time-honored engine of the Tweener especially for the applications targeting a mobile device which is not allowed to run Adobe's Flash Player, as needing AS3's type declaration will soon come the must thing in case of compiling the .swf (ABC) to the native binary (ex. armv6/7).


import net.kawa.tween.KTween;
import net.kawa.tween.easing.*;

public function run():void {
    KTween.to(mySprite, 2, {alpha: 0.0}, Linear.easeOut, callback);
    KTween.from(mySprite, 3, {x:320, y;480}, Quad.easeOut).round = true;
The syntax looks like the TweenMax series. This means the users could easily transfer to the new engine.


  • Free under the MIT license. Original. written from scratch.
  • ActionScript 3.0. Flash 9/10 and later.
  • Simple. Shorter source code. Less file bytes.
  • Much faster than Tweener and GTween. Bit faster than TweenNano and BetweenAS3.
  • AS3 type declaration checking available for the options of KTween
I like the code auto completion with the AS3's type declarations. This makes the developing more confortable.

See more detail on Google Code.


- .swc distribution in addition to .as source files.
- get the adoption on the Wonderfl!

Comments for this is fully welcome. Thanks in advance. Enjoy!

The original post of this is written in Japanese.(日本語ポストはこちら)