Quick answer: For a fast one-off, open the video in Photos → Share → Mail → choose Small. For batch compression or better results, use MediaOptim Mobile or the Shortcuts app with an "Encode Media" action.
How to Compress Video on iPhone
A 1-minute 4K video from your iPhone is 400 MB. Here are 5 methods to shrink it — including one warning that catches most people off guard.
Before you record: prevent the problem
The most overlooked tip: change your camera settings before shooting. Go to Settings → Camera → Record Video. You'll see the storage cost per minute for each format.
| Format | Size per minute | Best for |
|---|---|---|
| 4K 60fps | ~400 MB/min | Action, sport — overkill for casual video |
| 4K 30fps | ~170 MB/min | High quality when needed |
| 1080p 60fps | ~90 MB/min | Good balance for most situations |
| 1080p 30fps | ~60 MB/min | Everyday video — recommended default |
| 1080p HEVC | ~30 MB/min | Smallest without visible quality loss |
Switching from 4K 60fps to 1080p HEVC uses 13× less storage — no compression needed.
5 Ways to Compress Video on iPhone
Trim in Photos (native, free — but read the warning)
Built-in- 1.Open the video in the Photos app
- 2.Tap Edit in the top right
- 3.Drag the yellow handles on the timeline to cut the clip
- 4.Tap Done → Save Video (saves trimmed version) or Save Video as New Clip (keeps original)
Watch out: After trimming, iPhone keeps the full original in the background unless you specifically choose "Save Video" (which replaces it). The file size only drops after you delete the original. This is the #1 reason people trim and see no storage change.
Share with size selection (Mail or Messages)
Built-in- 1.Open the video in Photos
- 2.Tap the Share button (box with arrow up)
- 3.Choose Mail
- 4.iOS shows a size selector: Small, Medium, Large, Actual Size
- 5.Choose Small or Medium — this compresses the video before attaching
Watch out: This only works when sharing via Mail or certain apps. The compressed copy is sent but not saved to your camera roll — your original stays at full size.
Shortcuts app (automated, free)
Built-in- 1.Open Shortcuts and search for "Compress Movie" or create a new shortcut
- 2.Add the "Encode Media" action
- 3.Set resolution (720p = good balance of quality and size)
- 4.Run the shortcut on your video from the Share sheet
- 5.The compressed version saves to Photos
iMovie on iPhone (free)
Built-in- 1.Open iMovie and create a new Movie project
- 2.Import your video
- 3.Tap the Share button → Save Video
- 4.Choose resolution: HD 1080p or HD 720p
Watch out: iMovie re-encodes with H.264, which is less efficient than H.265. The file may not shrink as much as expected.
MediaOptim Mobile (best quality/size ratio)
- 1.Download MediaOptim from the App Store
- 2.Open the app and select your video (or entire camera roll)
- 3.Choose a compression preset
- 4.Compress — originals are kept until you confirm deletion
Which Method to Use — By Goal
The best compression method depends on what you're trying to do with the video.
Share directly — WhatsApp compresses automatically. For higher quality, send as a Document instead of a video.
Use Mail share with "Small" size for short clips. For longer videos, share a link via iCloud Drive instead.
Instagram recompresses anyway. Export at 1080p H.264 — no need to over-optimize.
MediaOptim Mobile or Shortcuts with 720p/H.265. Saves to Camera Roll at original quality for browsing.
Don't compress. Send the original. Metadata and quality matter in official contexts.
H.265 at high quality. Keeps everything, 30–50% smaller than H.264.