Video · Change Speed
Twice the speed, and the voice still sounds human.
Choose any speed from 0.25× to 8× for a single video, or split it so one moment plays in slow motion while the rest runs normally. A batch of videos takes 0.5× to 4×.
One-time purchase · macOS 26 Tahoe or later, Apple silicon recommended
How it works
Three steps, start to finish.
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01
Open Change Speed
Press ⌃⌥Space and type “slow motion”, or pick it from MightyBench’s menu bar icon.
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02
Pick a speed, or split first
Choose 0.25× to 8× for one video, or split the timeline and give each clip its own speed. Several videos share one speed from 0.5× to 4×. Leave Keep pitch on.
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03
Press Change Speed
You get an MP4 at the new speed in a new dated folder in Downloads › MightyBench. The original stays exactly as it was.
The details
Small things, done properly.
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Voices keep their pitch
With Keep pitch on, audio stays at its natural pitch, so a 2× lecture is quick but never squeaky.
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Slow motion for one moment
Split the timeline and give each clip its own speed, so a slow-motion moment can sit inside an otherwise normal video.
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From 0.25× up to 8×
A single video takes any speed from quarter speed up to 8×, set separately for each clip.
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A whole batch at one speed
Drop a folder of recordings and speed them all up, or slow them all down, at one setting between 0.5× and 4×.
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Opens MKV, AVI and MTS too
Drop in MOV, MP4, M4V, MKV, WebM, AVI or MTS files; every result comes out as an H.264 MP4 with AAC audio.
Specs
Change Speed, at a glance.
Faster or slower, voices intact.
| Opens | MOV, MP4, M4V, MKV, WebM, AVI, MTS |
|---|---|
| Saves as | MP4 (H.264, AAC) |
| Settings |
|
| Needs | FFmpeg, installed in one click |
| Originals | Never changed |
| Saved to | Downloads › MightyBench › date Change Speed |
FAQ
Questions about Change Speed
Anything else? Email support@mightybench.com and a person will reply.
How do I speed up a video on a Mac?
Open Change Speed, drop the video in, pick a speed such as 2× and press Change Speed to get a faster MP4.
Will voices sound squeaky when sped up?
No. With Keep pitch on, audio keeps its natural pitch, so speech is quicker but never squeaky.
Can I slow down just one part of a video?
Yes. Split the timeline and give that clip its own speed, anywhere from 0.25× to 8×, while the rest plays normally.
What are the slowest and fastest speeds?
A single video goes from 0.25× to 8×. When you process several videos at once, the range is 0.5× to 4×.
Do I have to install FFmpeg myself?
No. MightyBench sets FFmpeg up through Homebrew in one click. Already have it? Point MightyBench to your copy instead.
Is the original video replaced?
No. The result is published to a fresh dated folder in Downloads › MightyBench, and your original is never overwritten.
Plus forty-eight other tools.
Change Speed comes with every other MightyBench tool: video, audio, images, PDFs and on-device AI in one native Mac app. Pay $39 once for one Mac, with every MightyBench 1.x update included.
One-time purchase · macOS 26 Tahoe or later, Apple silicon recommended