How to compress a video on iPhone
To reduce an existing video, save a copy at a lower resolution or trim the parts you do not need. Compare the copy with the original before you decide what to delete. The file size depends on the clip and export settings.
Choose a tool and keep the original
Apple offers a free route through iMovie export at a lower resolution. Gallery Checkup offers trim and compression tools alongside photo review. Its exports create a new MP4 file.
Both approaches need room for a new copy. If your phone is full, first remove an unneeded download or transfer a file you can verify elsewhere. Do not delete the only copy of a video to make room for its export.
Compress with Gallery Checkup
- Open a video from a cleanup bundle.
- Choose Save space.
- Choose Compress.
- Select 1080p, 720p, or 480p.
- Choose Process video and wait for the new copy to save.
- Cancel the original-deletion prompt if you have not checked the export.
Play the saved video in Photos. Check sound, duration, orientation, and fine detail before you remove the original. If the source is in iCloud, the phone may need to download it first.
Choose resolution for the way you use the video
- 1080p: start here when detail matters.
- 720p: consider it for smaller screens or a smaller file.
- 480p: inspect text and faces carefully; less detail remains.
A smaller resolution does not guarantee a specific file size. Existing compression, movement, frame rate, and duration affect the result. Keep the original for future edits or large-screen use when quality matters.
Trim instead when only part of the clip matters
Choose Trim in the same tool, set the start and end points, and process the selection. Review the saved copy before you accept removal of the original. Compression keeps the full duration; trimming removes time from the copy.
Measure the result instead of trusting the estimate
- Open the original video details in Photos and note its file size.
- Export one copy at your chosen resolution.
- Note the saved copy size and compare playback.
- Calculate the difference: original size minus copy size.
The app shows an estimate before export. That estimate is not a measured result or a promised saving. Keeping both files uses more space. Deletion, Recently Deleted, and iCloud optimization affect the space available on the phone.
For the broader process, read how to free up iPhone storage.