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Why Are iPhone Videos So Large? 4K, 60 fps, HDR and ProRes Explained
iPhone videos are large because the camera records a lot of data per second: 4K resolution, 60 frames per second, HDR, and on Pro models optionally ProRes, which Apple says is up to 30 times larger than HEVC. Lower the resolution and frame rate in Settings, or shrink clips on your Mac afterward.
What makes an iPhone video file so large?
Four camera settings drive it, from most to least costly:
- ProRes. A professional editing format. Apple states that ProRes files are up to 30 times larger than HEVC files. Only recent Pro and Pro Max iPhones offer it.
- 4K resolution. Four times the pixels of 1080p.
- 60 fps. Twice the frames of 30 fps, with a bigger gap on busy footage.
- Formats. High Efficiency (HEVC) is smaller than Most Compatible (H.264).
HDR and Dolby Vision add color data on top. Apple does not publish a per-setting size table we could confirm, so we measured the pattern below instead of quoting one.
How much do 4K, 60 fps and HEVC change the size?
We could not use iPhone footage, so we took a 4-second synthetic 4K, 60 fps clip and encoded it with the same quality setting (H.264, CRF 23, ffmpeg 8.1.1, Apple M2 Pro, 8 November 2026). Only resolution and frame rate changed.
| Setting | Size (4 s clip) | Versus 1080p30 |
|---|---|---|
| 4K, 60 fps | 21.0 MB | 9.7x |
| 4K, 30 fps | 15.6 MB | 7.2x |
| 1080p, 60 fps | 2.3 MB | 1.07x |
| 1080p, 30 fps | 2.2 MB | 1x |
Two takeaways. Going from 4K to 1080p is by far the largest change. And 60 fps adds a modest amount on easy footage, though the gap grows with motion. Real iPhone clips will not match these ratios exactly.
For codec, we ran the 4K60 clip through the macOS command avconvert to 1080p. The H.264 preset made 8.0 MB and the HEVC preset made 7.2 MB, about 10% smaller. Hardware encoders aim at a bitrate, so the HEVC gain was modest here. See H.265 vs H.264 for a longer test.
How do I record smaller iPhone videos?
Open Settings > Camera. Then:
- Record Video: pick a lower resolution and frame rate, such as 1080p at 30 fps. On newer iPhones you can also tap the quick toggles in the top-right of the Camera app in Video mode.
- Formats: choose High Efficiency to record HEVC. Most Compatible records H.264.
- Formats > Apple ProRes: leave it off unless you are editing the footage.
One tradeoff: Apple notes that 1080p or lower and 60 fps or lower are more broadly compatible with older devices. A smaller setting also plays everywhere. Keep 4K for footage you will crop or edit.
How do I shrink an iPhone video on my Mac?
AirDrop the file to your Mac (see why a video is too large to AirDrop), then re-encode at a lower resolution. The free built-in route is QuickTime Player: open the clip, choose File > Export As, and pick 1080p. The command line version:
avconvert --preset PresetHEVC1920x1080 --source IMG_0001.MOV --output IMG_0001-small.movOn our 4K30 test clip this took 15.6 MB to 4.5 MB. Step-by-step guides: compress 4K video on Mac and compress video on Mac. There is also a page for iPhone video on Mac.
When is Smol the wrong tool for this?
For one clip, QuickTime Player or avconvert is enough. They are free and already installed. Changing the iPhone setting also fixes the problem at the source for future clips.
Smol earns its $29 when you have a camera roll worth of clips. Drop a folder of iPhone videos, photos and PDFs in together, or use the Finder right-click action. It outputs MP4, MOV, WebM or MKV with H.265 by default, a quality label or exact CRF, optional lower resolution, and audio can be removed. Nothing is uploaded, and originals stay untouched by default. Smol costs $29 once for one Mac. For a comparison, read the best video compressor for Mac.
How we checked this
Encoded a 4-second synthetic 4K60 clip at four resolution and frame-rate combinations with ffmpeg 8.1.1 on an Apple M2 Pro (macOS 27.0.1), and ran avconvert H.264 and HEVC 1080p presets. Read Apple’s ProRes support page. No iPhone footage was tested. Facts last checked . We make Smol, so treat our claims about it with the same care as any vendor’s, and see our editorial policy.
iPhone video size: common questions
Is 4K 60 fps worth the file size on iPhone?
Only for footage you plan to edit, crop or slow down. For sharing, 1080p at 30 fps looks fine on most screens and is far smaller. In our test, 4K60 was about 9.7 times larger than 1080p30 at the same quality setting. Record at the lowest setting that serves the final use.
Does HEVC make iPhone videos smaller than H.264?
Yes, though how much depends on the encoder. In our avconvert test, HEVC came out about 10% smaller than H.264 at the same 1080p60 size. High Efficiency is the iPhone default and the right choice unless you need older devices to play the file.
Why is my iPhone ProRes video so big?
ProRes is an editing format that keeps much more data per frame so it holds up through color grading. Apple says ProRes files are up to 30 times larger than HEVC files. Turn it off in Settings > Camera > Formats unless you are editing.
Does HDR make an iPhone video larger?
HDR stores extra color and brightness information, which adds some data. We did not measure it separately, so we cannot give a figure. Turning off HDR video in Camera settings is an option if you need to cut size, but resolution and frame rate matter more.
Does AirDrop shrink iPhone videos?
No. AirDrop sends the original file as recorded. If a 4K60 clip is large on the phone, it is just as large on the Mac. Compress it afterward with QuickTime Player, avconvert or a batch tool.
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