How to speed up a video on your iPhone

One of the prime rules of filmmaking is that everything should be onscreen for a reason — and unless your last name is Kubrick or Tarkvosky, you should probably be cutting or speeding up slow sequences, even on your iPhone. Here’s how to speed things up via iMovie, or return a video shot in slow-motion to normal speeds.

How to speed up a video in the iMovie app

iMovie is a free Apple app that offers more advanced editing than the options built into your iPhone, but is still aimed at casual users — you won’t be overwhelmed the way you might with Final Cut Pro or LumaFusion.

Here’s what to do:

• In iMovie, open or create a movie project.
• Tap your video clip in the timeline to show the inspector menu at the bottom of the screen.
• Tap Speed (the speedometer icon).
• Drag the yellow range handles to determine what section will be affected.
• In the inspector menu, drag the slider to the right to increase speed, or left to slow down. You’ll see a multiplier indicating how fast the clip is going (1/2X, 2X, etc.).
• When you’re done, tap outside the inspector.

Note that iMovie automatically preserves the audio pitch of sped-up sequences to prevent a “chipmunk” effect. If you want audio to change, usually for comedic effect, toggle Project Settings > Speed changes pitch.

How to undo a slo-mo video and change it to normal speed

Within an iMovie project, you can alter a clip’s speed in either direction by manually adjusting the Speed slider (see the instructions above). If you want to undo adjustments already made in that app, use Speed’s Reset in the inspector option with a clip selected.

Compatible iPhones can shoot videos using an official “Slo-mo” mode, however, and these are even easier to convert — no iMovie necessary. Follow these steps:

• Find the video in the Photos app. Under Albums, there’s a Slo-mo media type to make this easier.
• Open the video, then tap Edit.
• You’ll see a slider at the bottom with vertical lines. Slow-motion sequences are indicated by lines spaced far apart, with two taller lines bookending them. Drag one of those bookends towards the other until the slow-motion content is gone.
• Tap Done.

If you change your mind, you can always return to a video’s starting state using Edit > Revert > Revert to Original.

Read more: How to shoot and export ProRes video on your iPhone