How to change video speed on iPhone and Android
Your phone can already do basic speed changes. Here is what each built-in option can and cannot do, and when a browser tool is the simpler route.
Option 1: in your browser, on any phone
- Open vidspeed.app in Safari or Chrome.
- Tap Choose a video and pick a clip from your library.
- Choose a speed from 0.25× to 4× and whether to keep the voice’s pitch.
- Open More options and select 720p max. That keeps memory use low.
- Tap Change speed, keep the tab open until it finishes, then tap Download MP4. On iPhone, Safari saves it to Files; long-press the preview and choose “Save to Photos”, or open the file from Files and share it to Photos.
Phone limits: the export runs on your phone’s processor without hardware encoding, so a one-minute clip can take several minutes. If the tab reloads mid-export, the browser ran out of memory: trim the clip or lower the resolution.
Option 2: iPhone and iPad
iMovie (free from Apple)
- Open iMovie, tap Start New Project → Movie, select your clip and tap Create Movie.
- Tap the clip in the timeline, then tap the speed button (the clock icon).
- Drag the slider towards the hare to speed up (up to 2×) or the tortoise to slow down.
- Tap Done, then share or save the video.
Slo-mo clips in Photos
Videos shot in the Camera app’s Slo-mo mode have an adjustable slow section. In Photos, tap Edit and drag the tall markers under the frame viewer to choose where the slow part starts and ends. Photos cannot slow down or speed up normal videos; use iMovie or the browser for those.
Option 3: Android
Android phones differ by maker. Many gallery apps, including Samsung Gallery, have a speed control in their video editor: open the video, tap the edit (pencil) icon and look for Speed. Google Photos can adjust the slow section of clips shot in slow-motion mode. If your phone has neither, the browser tool above works in Chrome on Android.
Which should I use?
| Need | Best option |
|---|---|
| Quick 2× on iPhone, with an edit afterwards | iMovie |
| Faster than 2×, or exact values like 1.35× | VidSpeed in the browser |
| Choose where Slo-mo starts | Photos → Edit |
| Reverse a clip | Reverse video tool |
| Long 4K clip | Do it on a computer: phones run out of memory |
Questions people ask
How do I speed up a video on my iPhone?
In Apple’s free iMovie app: start a Movie project, add the clip, tap it in the timeline, tap the speed (clock) button and drag the slider, which goes up to 2×. For up to 4× without installing anything, open vidspeed.app in Safari and use the tool there.
Can I change the slow part of an iPhone Slo-mo video?
Yes. Open the video in Photos, tap Edit, and drag the tall white markers on the timeline to set where the slow section starts and ends.
Does it work in Safari and Chrome on phones?
Yes. The same tool runs in mobile browsers. Phones give each tab far less memory than a computer, so keep clips short (under about a minute) and choose 720p output in More options.
Is it safe to use on my phone?
The video is processed inside the browser tab, and nothing is uploaded. The first run downloads the roughly 31 MB video engine, so use Wi-Fi if data is limited.