Change the clip play speed to accelerate or decelerate its audio, animation, or particle effect. Changing the clip play speed affects the duration of the clip. You can only change the play speed for Animation clips, Audio clips, and Control clips.
To change the clip play speed, first, select the Edit mode to determine how other clips on the same track are affected:
Select the clip and set the Speed Multiplier property in the Inspector window. The Speed Multiplier property displays the play speed as a multiplier of the original clip speed.
Speed Multiplier in the Inspector window
When the Speed Multiplier is set to 1, the clip plays at its original speed. To double the play speed, change the Speed Multiplier to 2. This changes the duration of the clip. For example, doubling the play speed of a 180 frame Animation clip changes its duration to 90 frames.
A short-dashed line and multiplication factor of 2.00x indicates a clip playing at double its original speed
There are other ways to change the play speed of a clip:
Note: The clip play speed only recognizes positive values 0.001 and greater. You cannot set the clip play speed to a negative value. This does not, for example, play an Animation clip in reverse.