How to speed up or slow down a video on your Mac

To speed up or slow down a video on a Mac, put it in iMovie, click the Speed button and pick Slow, Fast or Custom. Photos can only slow a video down, and only one shot at a high frame rate. QuickTime Player can't save a speed change. Koi does it in one drag: drop the video on Speed and pick 0.5×, 1.5×, 2× or 3×, the sound keeping its pitch.

We make Koi, so read the Koi part with that in mind. Everything about Koi here is what version 1.13 does. Apple's steps come from its iMovie and Photos guides, checked October 21, 2026.

1. Put the video in an iMovie project and select it in the timeline.
2. Click the Speed button above the viewer.
3. Choose Slow or Fast in the Speed menu, then click a speed. Custom lets you type your own.
4. Select Preserve Pitch so voices don't go deep or squeaky.
5. Choose File, Share, File to save it.

Slow starts at 50% and Fast at 2×. To change just part of a clip, hold R and drag across it first. Smooth eases into the change, and Reverse plays the clip backwards. All of it is in Apple's iMovie guide.

On macOS Sequoia or later, Photos can play a video slower, if it was shot at more than 30 frames a second. Double-click the video, click Edit, and use the speed menu at the bottom of the video.

• Half speed needs a video shot at 60 frames a second or more.
• Quarter and One-fifth need 120 frames a second or more.
• For a slo-mo video, drag the white lines on the timeline to set where the slow part starts and ends.

Apple explains it in How to edit videos. Photos can't speed a video up.

1. Start dragging the video in Finder or on your desktop.
2. While you're still holding it, press and hold Shift. The video wheel opens round your pointer.
3. Drop the video on Speed. Its window opens with the video playing.
4. Pick 0.5×, 1.5×, 2× or 3×. You see and hear it at that speed straight away, and the new length shows.
5. Click Save. The copy lands beside the original and shows in Finder.

• The sound keeps its pitch, so voices sound normal, just faster or slower.
• The picture is encoded again in H.264, which plays nearly everywhere.
• The original is never touched. It runs on your Mac. Nothing is uploaded.

A tutorial often needs the boring part fast and the important part at normal speed. Koi's Edit Video does that.

1. Drag the video, hold Shift and drop it on Edit.
2. Press C at each place where the speed should change, to split it into pieces.
3. Click a piece. Its panel shows speed tiles from 0.25× to 30×. Click one.
4. Sped-up and slowed-down pieces show in purple on a track of their own.
5. Click Export, pick MP4 or GIF, a quality and 24, 30 or 60 frames a second, and click Export Video.

30× turns a ten-minute install into twenty seconds. The sound keeps its pitch at every speed, and Undo works the whole way.

• Slow motion from an iPhone slo-mo clip: Photos, which is made for it.
• A whole clip at one speed: Koi's Speed. One drop, and you hear it before you save.
• A tutorial or a screen recording with slow bits: Koi's Edit Video, a speed for each piece, up to 30×.
• Playing a clip backwards, or easing into slow motion: iMovie's Reverse and Smooth. Koi does neither.

1. Drag the recording, hold Shift and drop it on Edit.
2. Click the clip, and pick 30× in its speed tiles. An hour becomes two minutes.
3. Mute it with the speaker button under the video: sound at 30× is just noise.
4. Click Export, pick MP4, 30 or 60 frames a second and a quality, and click Export Video.

For a timelapse of a drawing, a build or an install, this is often all the editing it needs. Want a slower part in the middle? Split it there with C and give that piece 1×.

• Slowing down a normal 30 frames a second video makes it look choppy, because there are no extra frames to show. Real slow motion has to be shot at a high frame rate.
• Watching a video faster in a player doesn't change the file. Anyone you send it to sees it at normal speed.
• Speeding a video up makes it shorter, and so a smaller file. Slowing it down does the opposite.
• For a GIF, speed it up first. A fast GIF of a slow action stays small.

Related: trim a video, edit a screen recording or make a GIF. The rest of the wheel is on the Shift wheel page.

iMovie and Photos are free. Koi has no free plan: Pro is $20 a month, or $192 a year, after a 3-day free trial that needs a card. Lifetime is paid once, from $59. The Shift wheel uses no AI, so it never counts against Koi's usage. See the plans.