Reason for default easing in Actuate?


I’ve been using Actuate for all my tweens for about a year and love it. Recently, I discovered something about it that’s made me curious. I’ve noticed that the default easing type is “Expo.easeOut”. In my experience, this tends to produce tweens that slow down significantly near the end (exponentially slower?).

The Actuate documentation says:
“The default is Expo.easeOut, but you can change the default equation through Actuate.defaultEase”

Why is this? I’m curious to know what the motivation for this is. It’s probably just me, but it took me a while before I realized that my tweens weren’t ending faster than expected - they were just going slowly near the end.

I guess I’d assumed that the default easing would be linear and constant (linear.easeNone ???).



For me, Expo.EaseOut is just the nicest animation. So, if ever I would be creating an Actuate Lib, I would default it to Expo.EaseOut myself.

BTW, even Big Companies use Expo.EaseOut, off course its not exactly the Actuate Lib.

If its still on the site, Intel and Microsoft uses Expo.EaseOut. and

Windows 10 start menu is also using a variant of Expo.EaseOut/In.

Thanks Dominic!

You raise a good point. I didn’t know that Expo.easeOut is so widely used. I think I was just used to the in-built AS3 tweening class which has a different type of default easing (Elastic.easeOut, I believe).

Thanks again!


Yep, simple “ease out exponential 1 second” is a really easy way to “class up” the presentation of anything you’re building. For a somewhat more aggressive tween, try Quad.easeOut.

Some things do need a linear tween, usually do it in the tween like this:

Actuate.tween (progress, 1, { x: 100 }).ease (Linear.easeNone);
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Thanks Joshua! Good to know and hear from the source :slight_smile: