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How to speed up or slow down a video on a Mac
By Himanshu Ranjan · Updated 8 November 2026
FileDial changes video speed in fixed steps: Cut › Speed up 2×, Cut › Slow down 0.5×, Cut › Reverse and loops of 2× or 3×. Select the video in Finder, hold the right Option key and choose the tool. It saves a new copy offline and leaves your original alone.
What FileDial offers
The speed tools sit under Cut and use fixed settings, which keeps the job to a couple of clicks.
- Cut › Speed up 2×: plays the video at twice the speed, so it is half as long.
- Cut › Slow down 0.5×: plays at half speed, so it lasts twice as long.
- Cut › Reverse: plays the clip backwards.
- Cut › Loop 2× and Cut › Loop 3×: repeats the clip two or three times in one file.
Steps
Each tool works the same way and can run on a batch of files.
- Select the video in Finder.
- Hold the right Option key to open the dial.
- Open Cut and choose the speed tool.
- Play the new copy to check it, and keep the original for another setting.
Getting the effect you want
Speeding up suits long, slow footage such as a timelapse of a build, a screen recording of a repetitive task or a commute. A faster clip also shrinks in length, so it tends to be smaller on disk, though check the result card for the real size. Slowing down suits sport and detail shots, but footage recorded at a normal frame rate looks choppier slowed than footage shot at a high frame rate.
For more than 2× or less than 0.5×, run the tool again on the result. Two passes of Speed up 2× give four times the speed. Each pass makes a new copy, so delete the intermediate file when you are done.
Speeding up a recording
A screen recording of a long task, such as an install or a render, can be sped up to a watchable length. Two passes of Speed up 2× give four times the speed, three give eight. Keep an eye on text: at high speeds, anything on screen becomes unreadable, so use the speed-up for passing time, not for explanation.
If the video has speech, the voice will sound unnatural when sped up. Remove the audio with Audio › Remove audio or add music with Combine › Add music.
Slow motion that looks good
Slow motion needs frames. Footage recorded at a higher frame rate holds enough pictures to play smoothly at half speed, while normal footage repeats or blends frames and can look stuttery. Check the footage before you promise a slow-motion shot.
Reverse and loop are fun with short clips. A two-second clip looped three times with Cut › Loop 3× makes a six-second video, which is handy for short social posts.
Settings, quality and common mistakes
Speed changes interact with frame rate and sound. Speeding up drops the time between frames, so motion looks natural at 2× for most footage but frantic past about four times. Slowing down stretches frames, and without enough source frames the motion looks stepped.
The sound changes as well. At double speed a voice rises in pitch and becomes hard to follow, and at half speed it drops and drags. For talking footage, speed changes are rarely the answer, and Cut › Remove silences… shortens a talk by cutting the pauses while the voice stays natural.
Common mistakes: speeding a clip up before trimming, which processes more footage than needed, running Reverse on a clip with speech, which makes the sound unintelligible, and forgetting that each pass is a new file, so a stack of intermediate copies fills the disk.
FileDial is the right tool for quick, fixed changes like 2× and 0.5×. It is not the right tool for gradual speed ramps or for changing speed by an exact factor such as 1.5×, where an editor with a speed control is better.
File size consequences
A clip sped up 2× is half as long, so it is usually smaller on disk, though the video is re-encoded and the exact size depends on the content. A slowed clip is twice as long and is usually larger. Looping multiplies the length, so Cut › Loop 3× makes a file about three times the duration, and the size grows in the same direction.
Check the result card for the real sizes, and use a Compress tool when a looped or slowed clip becomes too big for its destination. This is especially relevant for social uploads and chat limits, which the other guides cover.
Related fixes
Audio changes with speed, so a sped-up voice sounds high-pitched. If you only want the picture, run Audio › Remove audio first. To keep only the best moment, trim before changing speed with Cut › Trim… To remove dead air from a talk, Cut › Remove silences… cuts the picture along with the sound.
QuickTime Player has no speed control. iMovie has speed controls for clips in a project, which is a better choice when you want varying speed within one video.
Questions
How do I speed up a video on a Mac?
Select the video in Finder, open FileDial with the right Option key and run Cut › Speed up 2×. It saves a new copy that plays at double speed. Repeat on the result for faster speeds. Each pass makes a new copy, so for stronger effects run the tool again on the latest result and delete the middle files.
Can I make slow motion from a normal video?
Cut › Slow down 0.5× plays the clip at half speed. Footage shot at a normal frame rate can look choppy when slowed, so slow motion looks best on clips filmed at a high frame rate. Frame rate matters more than the tool, because only footage recorded at a high rate holds enough frames for smooth slow motion.
Can I play a video backwards?
Yes. Run Cut › Reverse and a new copy plays backwards. Use Cut › Loop 2× or Loop 3× if you want the clip to repeat. Loops and reverse are separate tools under Cut, so a clip can be reversed first and looped afterwards.
Does QuickTime Player change speed?
Not that I can confirm from Apple's guide, which lists trim, rearrange, rotate and similar edits but not speed. iMovie has speed controls inside a project if you want flexible changes. If you need varying speed inside one video, an editor that supports speed ramps suits that better than fixed steps.