How to speed up or slow down ANYTHING in After Effects

Whether you are using After Effects for motion design or for visual effects, there are several ways to speed up or slow clips, layers, keyframes, and comps. In this post, I’ll cover each technique for changing speed in After Effects.

Time remapping

Any footage layer or pre-comp has the option to enable time remapping.

To enable time remapping right click on the layer, select Time > Enable Time Remapping.
: ⌥ + ⌘ + T
Win: CTRL + Alt + T

By default, After Effects will add 2 keyframes to the Time Remap property of your layer – one at the beginning and one at the end. If your layer is trimmed, you might want to add additional keyframes to beginning and end before editing. These keyframes are linked to the playback time of the footage (or comp).

You can speed things up by moving the keyframes closer together, or you can slow things down by moving them further apart. Keep in mind that you will want to trim the actual layer accordingly.

You can also change the value of the keyframes and add easing to any of the keyframes. This makes time remapping an ideal option for creating speed ramps and doing other non-linear time adjustments.

To reverse the speed, you can select the Time Remap keyframes then choose Keyframe Assistant > Time Reverse Keyframes.

Time stretching

Any layer has the option to time stretch.

This can be accessed by right clicking on the layer and selecting Time > Time Stretch. This will pull up a menu where you can either change the “Stretch Factor” or the time of the “New Duration.” Then click OK to execute the change.

You can also edit time stretching straight from the timeline. With the Stretch column visible, you can drag the percentage or you can hold ⌥ / Alt and drag the in or out point of a layer. Either way, the Stretch percentage and your layer will adjust accordingly.

Similar to time remapping, time stretching will adjust the playback time of your footage. But it also adjusts any existing keyframes on the layer and the in or out point of the layer too.

Time stretching is non-destructive, meaning you can revert your layer back to 100% at any time. It also means that if you are adjusting a pre-comp, the contents of the comp won’t change at all – After Effects will just stretch the pre-comp accordingly.

To reverse the speed, you can change the time stretch value to a negative value like -100%.

Keyframe expanding & contracting

If you have a property with 2 or more keyframes, it is easy to speed them up or slow them down.

Select the keyframes you’d like to adjust, then holding ⌥ / Alt and reposition the first or last keyframe in your selection. As you move the keyframe all the keyframes in your selection will shift proportionally.

To reverse a selection of keyframes right click, then select Keyframe Assistant > Time Reverse Keyframes.

Speed (Script UI Panel)

The techniques above work well, but for even more control over retiming things in After Effects there is Speed. Speed is an After Effects Script UI Panel that lets you quickly and precisely retime any selection of layers, keyframes, or entire comps.

Speed features a compact, easy to use, interface that includes a live preview so you can see the new duration in the timeline before you make any changes.

Speed will automatically adjust the keyframes and in/out points of your selection proportionally. You can also use Speed to automatically add time remapping keyframes to your footage or instead adjust everything via time stretching.

Another powerful feature of Speed, is nudging. This allows you to adjust the speed of a selection, while nudging the unselected layers or keyframes around it proportionally.

You can reverse the timing of anything in After Effects with the Reverse Speed button in the Speed panel.