The fastest way to slow a video on iPhone
Open the video in the Photos app, tap Edit, then tap the three dots and select Video Speed. You'll see options from 0.5x (half speed) to 2x (double speed). Choose your speed, tap Done, then Save Video. The slowed video saves as a new file, leaving your original untouched.
This method works on iPhone 13 and newer. If you have an older model, you'll need to use a third-party app instead — the built-in speed control isn't available before iOS 17.
The speed options are fixed: you can only choose 0.5x, 0.75x, 1x (normal), 1.25x, 1.5x, 1.75x, or 2x. You cannot set a custom speed like 1.3x or 0.6x using the Photos app alone.
Key Takeaways
- iPhone 13 and newer can slow video directly in the Photos app using the Video Speed tool, without installing anything extra.
- Older iPhones require a third-party app like iMovie, Slow Fast Slow, or Adobe Premiere Rush to change video speed.
- The Photos app offers seven fixed speed options from 0.5x to 2x, but does not allow custom speeds between those points.
- Slowing a video in Photos creates a new file; your original video is never changed.
Using iMovie if you have an older iPhone
iMovie comes pre-installed on most iPhones and works on models going back to iPhone 6s. Open iMovie, tap the plus icon, select Movie, then choose your video from your library. Tap the video in the timeline to select it, then tap the speedometer icon at the bottom of the screen.
Drag the slider left to slow down or right to speed up. iMovie shows you the speed as a percentage — 50% is half speed, 100% is normal, 200% is double speed. You can set any speed between 0.1x and 2x, giving you much finer control than the Photos app. When you're done, tap Done, then tap Share to save your edited video.
iMovie saves the edited video to your Photos library. The export can take several minutes depending on how long your video is and how much you've slowed it down.
Third-party apps with more control
If iMovie feels limited or you want more editing options alongside speed control, Adobe Premiere Rush and Slow Fast Slow both let you set custom speeds and preview changes in real time. Adobe Premiere Rush is free with a Creative Cloud account (or you can use it with limited features without one). Slow Fast Slow is a paid app focused specifically on speed ramping — it's useful if you want to slow some parts of a video while keeping others at normal speed.
Both apps let you export at different resolutions and frame rates. If you're slowing a video significantly — say, to 0.25x — exporting at the original resolution may create a large file. You can usually reduce the export quality to save space, though this makes the video slightly less sharp.
Why slowed video takes up more storage
When you slow a video, the file size often grows because the app has to fill in more frames. A video slowed to 0.5x (half speed) plays for twice as long, so it contains roughly twice as much data. If your original video was 500 MB, the slowed version might be 900 MB or larger depending on the app and export settings.
You can reduce file size by lowering the export resolution — 1080p instead of 4K, for example — or by reducing the frame rate from 60 fps to 30 fps. The trade-off is visible softness in the video, especially if you're watching on a large screen.
When slowing video causes audio problems
Slowing video also slows the audio, which can make speech sound unnatural or distorted at very slow speeds (below 0.5x). If you want to keep the audio at normal speed while slowing the video, you'll need to separate the audio and video tracks — most third-party apps like Adobe Premiere Rush let you do this, but the Photos app and iMovie do not.
Some apps will mute the audio automatically if you slow below a certain threshold, or they'll let you delete the audio track entirely so you can add music or narration later. Check the app's settings before exporting to see what happens to sound.
Exporting and sharing your slowed video
After you've slowed your video, the app will ask where to save it. Most apps save to your Photos library by default, which makes the video available in the Photos app and easy to share via Messages or email. Some apps also let you save directly to iCloud Drive, Google Drive, or Dropbox.
If you're sharing the video online — to TikTok, Instagram, or YouTube — check the platform's file size and format limits before exporting. Instagram, for example, prefers videos under 4 GB and accepts MP4 or MOV format. Exporting at a lower resolution saves time uploading and reduces the chance of the platform re-compressing your video.
Frequently Asked Questions
Can I slow just part of a video, not the whole thing?
The Photos app and iMovie slow the entire video uniformly. To slow only a section, you need Adobe Premiere Rush or Slow Fast Slow, which let you split the video into clips and set different speeds for each. This is called speed ramping and is common in action videos or slow-motion effects.
What happens to the audio when I slow a video?
The audio slows along with the video, which can sound distorted or unnatural at very slow speeds. Most apps let you mute the audio or delete it entirely so you can add music or narration separately. The Photos app and iMovie do not offer separate audio control.
Will slowing a video make it look blurry?
Slowing does not add blur by itself, but exporting at a lower resolution to save file size will make the video appear softer. If you export at the original resolution and frame rate, the video should look as sharp as the original, just slower.
Can I undo a slowed video and get the original back?
Yes — the original video is never deleted. All apps save the slowed version as a new file. You can delete the slowed version and keep the original, or keep both.
What's the slowest speed I can set?
The Photos app's slowest option is 0.5x (half speed). iMovie and third-party apps typically go down to 0.1x or lower, though speeds below 0.25x often look choppy because the video doesn't have enough frames to fill the time smoothly.