Make a Slow Motion Video Online - Free

Slow motion, slow mo and slowmo are three names for one thing: a clip that plays slower than it was shot. Slowing a clip down stretches the frames it already has. Footage shot at 60 frames a second or more slows to half speed cleanly, because there are enough real frames to fill the time; a 30fps clip at half speed holds each frame for twice as long, so fast movement can look slightly steppy.

Half speed also doubles the length, so a 10-second moment becomes 20 seconds. Trim to the moment first and slow only that, and the result stays watchable.