The fastest way to slow down video on iPhone

Open the Photos app, find the video you want to slow down, tap Edit, then tap the speed icon (it looks like a speedometer) in the toolbar at the bottom. Slide left to make it slower — you can choose from half speed, quarter speed, or custom speeds anywhere between 0.5x and 1x normal speed. Tap Done to save the change.

This works on any iPhone running iOS 13 or later. The edit happens to your copy of the video, not the original, so you can always undo it by opening the video again and tapping Edit > Revert.

If you want to slow down video while you are recording it — not after — you need to use the Camera app's slow-motion mode instead. That is a different process and gives you different results.

Key Takeaways

  • The Photos app's speed control lets you slow any existing video to half speed, quarter speed, or any custom speed between 0.5x and 1x.
  • Edits in Photos are non-destructive — the original video stays unchanged, and you can revert any time by tapping Revert.
  • Slow-motion mode in the Camera app records video at a higher frame rate while you are filming, which is different from slowing down video after the fact.
  • Exporting a slowed-down video from Photos creates a new file; sharing it directly from Photos does not require export.

Using the speed slider in Photos

When you tap the speed icon in the Photos editor, a slider appears with preset speeds marked: 0.5x (half speed), 0.25x (quarter speed), and 1x (normal). You can tap and drag the slider to any point between 0.25x and 1x to set a custom speed — for example, 0.7x or 0.3x.

The slider shows you the duration of the video at each speed. If your original video is 10 seconds long, slowing it to 0.5x makes it 20 seconds; slowing it to 0.25x makes it 40 seconds. This helps you see how much longer the video will be before you commit to the change.

Once you tap Done, the change is saved to your Photos library. If you later decide you want a different speed, open the video again, tap Edit, and adjust the slider to a new value.

Recording in slow-motion mode while filming

If you want to capture slow-motion video as you record, use the Camera app instead of Photos. Open Camera, swipe left until you see Slo-Mo, then record your video normally. The camera records at 120 frames per second (on most iPhones) or 240 fps (on newer models), which means the video plays back at one-quarter or one-eighth normal speed by default.

Slow-motion recording uses more storage because it captures more frames per second. A 10-second slow-motion clip can be 100 MB or larger, depending on your iPhone model and which frame rate you use.

After you record a slow-motion video, you can edit it in Photos to change which parts play in slow motion and which parts play at normal speed. Tap Edit, then tap the speed icon, and you will see a timeline with yellow markers. Drag the markers to choose which sections of the video stay slow and which speed up.

Exporting and sharing your slowed-down video

If you want to send a slowed-down video to someone or upload it to social media, you can share it directly from Photos without exporting. Open the video, tap the share icon (a box with an arrow), and choose your destination — Messages, Mail, AirDrop, or any app that accepts video.

If you need the video as a file on your computer, you can export it. Open the video in Photos, tap Edit, make sure your speed change is set, then tap Done. Next, tap the share icon and choose Save Video (on some iPhones) or use AirDrop to send it to a Mac. The exported file will be in the new speed you set.

Keep in mind that exporting a slowed-down video can take a few minutes, depending on the length and your iPhone's storage. The file size may be slightly larger than the original because the video now contains more frames spread across a longer duration.

Why slowing down video matters

Slow-motion video is useful for several reasons. It helps you see details in fast action — a sports move, a pet jumping, a child running — that happen too quickly to notice at normal speed. It also changes the mood of a video, making ordinary moments feel more dramatic or cinematic.

The difference between recording in slow-motion mode and slowing down video after the fact is important: recording in slow-mo captures more visual information, so the slow-motion playback looks smooth. Slowing down a normal-speed video in Photos stretches the frames that were already captured, which can look less smooth, especially if you slow it down a lot.

For casual use — slowing down a video you already have — the Photos app method is fast and built in. For intentional slow-motion shots, recording in Slo-Mo mode while filming gives you better results.

Troubleshooting slow-motion edits

If the speed icon does not appear when you tap Edit, your iPhone may be running an older version of iOS. The speed control was added in iOS 13. Check your iOS version by opening Settings > General > About and looking at the OS number. If it is lower than 13, update your iPhone by going to Settings > General > Software Update.

If a video is too short or too long, remember that slowing it down makes it longer. A 2-second video slowed to 0.25x becomes 8 seconds. If you are trying to fit a video into a specific time slot — like a social media post with a time limit — check the duration shown in the slider before you save.

If you accidentally saved a speed change you did not want, open the video again, tap Edit, and tap Revert to go back to the original speed. This works as long as you have not deleted the original video from your library.

Frequently Asked Questions

Can I slow down only part of a video?

Not with the basic speed control in Photos — that tool slows the entire video. However, if you recorded the video in Slo-Mo mode, you can edit which sections play slow and which play at normal speed by dragging the yellow markers on the timeline in the Photos editor.

Does slowing down a video reduce its quality?

No. Slowing down a video in Photos does not delete any frames or reduce resolution. It stretches the existing frames across a longer time, so the video stays as sharp as the original. The playback may look slightly less smooth than a video recorded in Slo-Mo mode, but the picture quality itself does not change.

What is the slowest speed I can set?

The slowest preset is 0.25x (quarter speed), but you can drag the slider to any custom speed down to 0.25x. You cannot go slower than that in the Photos app. If you need slower motion, you would need to use a third-party video editing app.

Will slowing down a video use more storage?

The edited version takes up about the same storage as the original because Photos stores the speed change as metadata, not as a new full-resolution file. Only when you export the video does your iPhone create a new file, which may be slightly larger because it contains more frames spread over a longer duration.

Can I undo a speed change after I have already shared the video?

Yes. The original video in your Photos library stays unchanged. Even if you have shared a slowed-down version, you can open the video in Photos, tap Edit, and tap Revert to go back to normal speed. Reverting only affects your copy — it does not change videos you have already sent to other people.