Essential After Effects Expressions Every Motion Designer Should Know

Here are the expressions I use on almost every project. Memorize these and your workflow will be significantly faster.

1. Wiggle — Random organic movement

wiggle(3, 50)

Adds randomness to any property. (frequency, amplitude)

2. LoopOut — Infinite loops

loopOut("cycle")

Loops your keyframed animation forever. Also try "pingpong" and "offset".

3. Time — Continuous change

time * 90

Multiplies time by a value. Great for endless rotation (this = 90°/second).

4. Value at Time — Reference past/future values

valueAtTime(time - 0.1)

Gets the property's value from a different time. Essential for follow-through/drag effects.

5. Linear / Ease — Value mapping

linear(time, 0, 3, 0, 100)

Maps one range to another. This maps time 0-3 seconds to value 0-100. ease() does the same but with easing.

6. Index-based offset — Staggered animations

delay = index * 0.1;

valueAtTime(time - delay)

Apply to multiple layers — each one starts slightly later based on its layer index. Creates beautiful cascade/stagger effects.

7. Random — Controlled randomness

seedRandom(index, true);

random(0, 100)

Generates random values. Using index as the seed gives each layer a unique but consistent random value.

8. If/Else — Conditional logic

if (time > 2) {

  100

} else {

  0

}

Changes values based on conditions. Great for triggering events at specific times.

9. Comp Size — Responsive positioning

[thisComp.width/2, thisComp.height/2]

Always centers the layer regardless of comp size.

10. toWorld / fromWorld — 3D space conversion

thisComp.layer("Target").toWorld([0,0,0])

Gets the world-space position of another layer. Essential for 3D expressions.

Pro tip: You don't need to be a JavaScript expert to use expressions. Start by copying these, modifying the numbers, and understanding what changes. The AE expression language is a subset of JavaScript — you'll learn it naturally through experimentation.