In this walkthrough, we've shared how to add keyframes in After Effects, so you can design complex animations that move smoothly over time, while only drawing a few frames in the sequence.
What is a Keyframe?
Keyframes mark a specific point in time where a layer changes. This could be a vector moving in space, a property adjustment (such as color or opacity), or a shift in an audio track. With After Effects, you create a beginning keyframe and an ending keyframe, and the software tries to fill in (or interpolate) all of the time in between.
To use keyframes, you'll need to activate the stopwatch, which sets up new keyframes whenever you adjust that layer. If the stopwatch is inactive, any tweaks made to a layer will last for the clip's entire duration, instead of being assigned a position on the timeline.
How to Add Keyframes in After Effects
First, load your current After Effects project and find the property that you want to adjust. If you click the stopwatch icon next to the property name, keyframing will be enabled. You can also go to "Animation" > "Add [x] Keyframe", and specify the layer that you want to animate.
Once you've gotten the hang of adding keyframes, you can try Auto-Keyframe mode. This adds a new keyframe whenever you make an adjustment to a layer, and at the current time where you are in the clip. To activate Auto-Keyframe mode, go to the Timeline panel and select "Enable Auto-keyframe".
Using the Keyframe Navigator
Once you've added a keyframe, After Effects will launch the Keyframe Navigator, which displays all of the keyframes for a particular layer. To move between keyframes, click the navigator arrow next to a desired keyframe, or press the K key to move to the next item in the sequence.
Selecting and Deleting Keyframes
When working in layer bar mode, you'll notice that the selected keyframes are colored blue, while the unselected ones are colored grey. Meanwhile, in Graph Editor mode, selected keyframes are yellow and unselected ones match their affiliated graph color. To select a keyframe, just click on the icon, or Shift+click to draw a marquee around multiple keyframes.
At any point in the animation process, you can delete a keyframe by selecting it and pressing Delete, or clicking the stopwatch icon next to the layer to deactivate all associated keyframes. Make sure to save a copy of your work before doing this, because those keyframes will be permanently deleted, and clicking on the stopwatch again will not reactivate them. However, you can always undo a keyframe action by selecting "Edit" > "Undo".