Modern iPhones record beautiful video, and enormous files to match. A few minutes of 4K can take up gigabytes, which fills your storage, slows down backups and makes videos hard to send. You can fix this from two directions: shrink the videos you already have, and change the camera settings so future videos are smaller.

Why iPhone videos are so big

File size depends mostly on three settings:

  • Resolution. 4K has four times the pixels of 1080p.
  • Frame rate. 60 fps records twice as many frames as 30 fps.
  • Format. iPhones can record in HEVC ("High Efficiency") or H.264 ("Most Compatible"). HEVC files are much smaller for the same quality.

Recording 4K at 60 fps in "Most Compatible" mode is the biggest combination there is. Most people never need it.

Shrink a video you've already recorded

The iPhone has no built-in "compress" button, but you can do it in your browser in a minute:

  1. In Photos, open the video, tap Share, then Save to Files. Choose a folder such as Downloads.
  2. Open Safari and go to the video compressor.
  3. Tap the upload box, choose Browse, and pick the video from Files. (You can also choose Photo Library directly.)
  4. Pick Balanced for most videos, or Smallest file if size matters more than quality.
  5. Tap Convert to MP4, then Download.
  6. Open the result in Files, tap Share, then Save Video to put it back in Photos.

Videos straight from an iPhone often shrink by half or more with Balanced, with little visible difference on a phone screen. Once you've checked the smaller copy, you can delete the original to free up the space.

Shrink it to a specific size

If you need the video under a hard limit, use a preset that aims for a target size:

Change camera settings so new videos are smaller

Open Settings, tap Camera, then:

Record Video. Choose 1080p at 30 fps for everyday videos. It looks great on phones, laptops and TVs, and takes a fraction of the space of 4K. The settings screen shows roughly how much space a minute of video takes at each option, so you can compare. Keep 4K for the moments you really want to keep in the best quality.

Formats. Choose High Efficiency to record in HEVC, which roughly halves file sizes. The trade-off is compatibility: some Windows PCs and older devices can't play HEVC. If you often share videos with those, our MOV to MP4 converter turns them into a universal format when needed. Our guide on converting MOV to MP4 explains the difference.

Slo-mo and Cinematic. These modes record at high frame rates or with extra depth data, which makes larger files. Use them on purpose, not by default.

Other ways to save space

  • Trim before you keep. Open the video in Photos, tap Edit and drag the ends of the timeline. Trimming 30 seconds of shaky start and end saves real space.
  • Use iCloud Photos with Optimize iPhone Storage. Under Settings → Photos, this keeps full-size originals in iCloud and smaller versions on your phone.
  • Delete duplicates and recently deleted items. Videos in Recently Deleted still use space for 30 days. Empty it to reclaim storage immediately.

Does compressing ruin quality?

Not if you choose sensible settings. Phone videos are recorded with a lot of headroom so they look good in any situation. A modern encoder can remove much of that extra data with little visible change, especially on small screens. For a deeper look at what's going on, see bitrate, resolution and frame rate explained.

Start with your biggest videos: open the video compressor and you'll free up space in minutes.