- How to speed up a whole clip in iMovie
- How to fine-tune the speed
- How to speed up just part of a clip
- Speed settings at a glance
- The catch: speeding up changes the sound too
- Speed up a video on iPhone
- Tips for good fast-motion video
- Exporting your sped-up video
- Slowing a clip down instead
- My verdict
- Frequently asked questions
To speed up a video in iMovie on a Mac, select the clip in the timeline, click the Speed button above the viewer, choose Fast from the Speed menu and pick a speed. A rabbit icon appears on the clip. Tick Preserve Pitch if the clip has talking, so voices don't sound squeaky.
Sped-up video is everywhere on social media: time-lapses of a workspace makeover, a quick tour, packing orders in fast motion. iMovie on a Mac can speed up a whole clip or just part of one, and there's one checkbox that stops your voice sounding like a cartoon.
How to speed up a whole clip in iMovie
- Open your project and select the clip in the timeline.
- Click the Speed button above the viewer (the speedometer icon).
- Open the Speed menu and choose Fast.
- Click one of the speed buttons to set how fast.
- If the clip has speech, tick Preserve Pitch.
A rabbit icon appears on the clip and it gets shorter in the timeline, which is a handy visual check that it worked.
How to fine-tune the speed
Every sped-up clip gets a speed slider at the top of it in the timeline. Apple says dragging it to the left speeds the clip up, and dragging it to the right slows it down. Watch the clip's length change as you drag, which makes it easy to fit a clip into a gap in your edit or to match a beat in the music.
How to speed up just part of a clip
This is the clever bit most people don't know about. You can speed up a boring middle section and keep the start and end at normal speed.
- Hold down the R key and drag across the part of the clip you want to change.
- Click the Speed button.
- Choose Fast. Apple says it defaults to twice normal speed (2x), and you can pick another speed button.
- Tick Smooth if you want the speed to ramp up and down gradually.
- Drag any of the speed sliders at the top of the clip to adjust each section.
Speed settings at a glance
| Option | What it does | Use it for |
|---|---|---|
| Fast | Speeds the clip up | Time-lapses, skipping dull bits |
| Slow | Slows the clip down (defaults to 50% for a selected range) | Dramatic moments, product reveals |
| Custom | Lets you type an exact speed | Matching a set length or music |
| Preserve Pitch | Keeps voices sounding normal | Talking-head or voiceover clips |
| Smooth | Ramps between speeds gradually | Part-clip speed changes |
| Reverse | Plays the clip backwards | Fun effects and loops |
The catch: speeding up changes the sound too
Apple explains that when a clip with audio plays faster, the pitch of the audio goes up. Speed a talking clip to double speed without thinking and everyone sounds squeaky. Tick Preserve Pitch above the viewer to keep the original tone. For fast time-lapses where the original sound doesn't matter, it's often better to turn the clip's volume right down and add music instead.
One more limit: Apple notes that Cinematic mode effects aren't compatible with speed changes. If you speed up a Cinematic mode clip from an iPhone, you can no longer adjust its focus in iMovie.
Speed up a video on iPhone
On the iPhone version of iMovie, tap the clip in the timeline and look for the speed control in the editing tools at the bottom. Drag the slider towards the rabbit to speed it up. There are fewer options than on the Mac, but it's fine for a quick fast-motion clip.
Tips for good fast-motion video
- Use a tripod or prop your phone up. Shaky footage looks worse when it's sped up.
- Film more than you think you need. Ten minutes at high speed becomes a short clip.
- Trim the start and end first by dragging the clip edges, then change the speed.
- Add music over sped-up sections instead of using the original audio.
- Keep one speed throughout a section so it doesn't feel jerky.
Exporting your sped-up video
When you're happy, choose File, Share, File to export. Speed changes are baked into the file, so they'll play the same wherever you post it. For more on producing short videos that work for your business, see my guide to making effective short videos.
Slowing a clip down instead
The same Speed button works the other way too. Choose Slow instead of Fast and the clip plays in slow motion, with a turtle icon on it. Apple says a slowed clip becomes longer in the timeline, and its audio pitch drops, so Preserve Pitch matters here as well. Slow motion works best on footage filmed at a high frame rate on your phone; normal footage slowed right down can look jerky.
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My verdict
Select the clip, click Speed, choose Fast and you're done. Hold R to speed up just part of a clip, use the slider for fine control and always tick Preserve Pitch when people are talking. For screen tutorials where you want to skip the waiting bits, record with one of my recommended screen recorders and speed up the slow sections in iMovie.
Frequently asked questions
How do I speed up a clip in iMovie on Mac?
Select the clip, click the Speed button, choose Fast from the Speed menu and pick a speed.
How do I speed up part of a clip in iMovie?
Hold the R key and drag across the section, click Speed and choose Fast.
Why does my voice sound squeaky after speeding up in iMovie?
Faster playback raises the pitch. Tick Preserve Pitch above the viewer.
How fast can iMovie speed up a video?
You can pick from the preset speed buttons or choose Custom and type a speed. A selected range defaults to 2x.
Can I speed up a Cinematic mode video in iMovie?
Yes, but you can no longer adjust its focus afterwards, because Cinematic effects aren't compatible with speed changes.
Can iMovie play a clip backwards?
Yes. Click Speed and tick Reverse.
