How to Apply an Expression to Multiple Layers in After Effects?

To apply the same expression to multiple layers in After Effects efficiently, the most common method is to copy the expression from one layer property and paste it onto the corresponding properties of other layers. This technique is highlighted as a time-saving approach, particularly when combined with keyboard shortcuts.

The Copy and Paste Expression Method

This method leverages After Effects' ability to transfer expressions between compatible layer properties. It's especially useful when you've refined an expression on one layer and want to duplicate its behavior across several others.

Step-by-Step Guide to Copying and Pasting Expressions

Applying an expression to multiple layers using copy and paste is a straightforward process:

1. Select the Source Layer: Begin by selecting the layer that already has the expression you want to copy.
2. Reveal Expressions: To quickly see all expressions on the selected layer, type ee on your keyboard. This shortcut is a key time-saver as mentioned in common After Effects workflows, allowing you to easily locate the expression property.
3. Select the Property with the Expression: Click directly on the specific property name (e.g., Position, Scale, Rotation, Opacity) that contains the expression you want to copy.
4. Copy the Property: With the property selected, press Ctrl+C (Windows) or Cmd+C (macOS) to copy it. This copies not just the property's value, but also any expressions applied to it.
5. Select the Target Layers: Select the layers you want to apply the expression to. You can select multiple layers by holding down Shift or Ctrl/Cmd while clicking on them in the Timeline panel.
6. Paste the Property and Expression: With the target layers selected, press Ctrl+V (Windows) or Cmd+V (macOS). After Effects will paste the copied property, including its expression, onto the selected layers. The expression will now control the corresponding property on each of the target layers.

This workflow, focusing on quickly revealing and selecting the expression property using ee before copying and pasting, is a powerful way to propagate animation and control logic across your composition, significantly speeding up your workflow.