Dual CameraHow to Compress a Video on iPhone
Four ways to make an iPhone video smaller, from the one Apple recommends to the camera settings that stop files getting huge in the first place. With real sizes.
Updated
A one-minute 4K clip from an iPhone is around 170 MB. At 60 frames per second it is closer to 400 MB. That is why a video that took ninety seconds to film will not go through Messages, sits in a Mail draft forever, and fills a phone faster than anything else on it.
There are four honest ways to make it smaller, and two popular ones that do nothing. Here they are in the order you should try them.
The short answer
| Method | How much smaller | Quality cost | Use it when |
|---|---|---|---|
| Export from iMovie at lower resolution | 4K to 720p: 85 to 90% | Visible on a big screen, not on a phone | You need one file to fit a limit |
| Trim the length | In proportion to what you cut | None | The clip has slack at either end |
| Let the sending app do it | Varies, no control | Often heavy | You just need it to arrive |
| Change the camera settings | Every future video, at the source | Chosen once, deliberately | Storage or sharing is a recurring problem |
Method 1: export from iMovie at a lower resolution
This is the method Apple documents in its own support article on compressing a video, and it is the one that gives you control over the result. iMovie is free, and if it is not on your phone it is a one-tap install from the App Store.
- Open iMovie, tap Start New Project, then Movie.
- Select the video from your photo library and tap Create Movie.
- Tap Done in the top-left corner.
- Tap the Share button, then Save or Share Video.
- Tap Options and choose a lower resolution.
- Choose Save Video, or send it straight on with Save to Files or AirDrop.
The original stays in Photos untouched. What you get is a second, smaller copy.
Apple gives these sizes for one minute of exported video:
| Export resolution | Size per minute | Good for |
|---|---|---|
| 1080p | 70 to 105 MB | Keeping most of the quality |
| 720p | 19 to 27 MB | Social media, most sharing |
| 540p | 12 to 16 MB | Chat apps |
| 360p | 6 to 9 MB | Text messages, when size is everything |
720p is the setting to reach for by default. It cuts a 1080p file to about a quarter and a 4K file to a small fraction, and on a phone screen the difference is hard to find. Go to 540p or 360p only when a hard limit forces you.
Apple’s article describes these steps for an iPhone 12 or later on iOS 26 with the current iMovie. Older combinations work the same way in practice, but the menu wording can differ.
Method 2: trim it
This is the only way to make a video smaller with zero quality loss, and it is the one people forget. A video’s size is almost exactly proportional to its length, so cutting the dead three seconds at the start and the fumble at the end takes the same percentage off the file.
Open the video in Photos, tap Edit, drag the yellow handles at either end of the timeline, and tap Done. Choose Save Video as New Clip if you want to keep the original.
Do this before you compress, not instead of it. A trimmed clip exported at 720p is smaller than either step alone.
Method 3: let the sending app do it
Messages, Mail and WhatsApp all shrink video on the way out. Sometimes that is exactly what you want: you need the clip to arrive and you do not care how it looks.
The catch is that you get no say in how hard they squeeze, and the results can be rough. If quality matters, compress it yourself first with Method 1 and then send the result, or send the original at full quality through a link instead. How to send a large video from iPhone covers every route and the size limit on each.
Method 4: stop recording huge files in the first place
If you keep having this problem, the fix is in the camera, not in iMovie. Apple’s advice in the same article is to record at a resolution below 1080p, turn off HDR Video, and make sure High Efficiency is selected. Here is where each of those lives.
Settings → Camera → Record Video. This is the resolution and frame rate for every video you shoot. 1080p at 30 fps is the sweet spot for anything that will live on a phone or in a feed. 4K at 60 fps produces files around six times larger and is worth it only if you will edit the footage or watch it on a large screen.
Settings → Camera → Formats → High Efficiency. This records in HEVC instead of the older H.264. Apple describes it as better compression at the same visual quality, and in practice it roughly halves the file. It is the default on any recent iPhone, so this is only worth checking if you or someone else changed it to Most Compatible at some point.
Settings → Camera → Record Video → HDR Video, off. HDR adds data per frame. It looks better on an HDR display and costs storage everywhere.
If you want to know what a setting will cost before you commit to it, the video file size calculator gives the size per minute for each resolution and format, and how many hours fit on your phone.
Two things that look like compression and are not
Zipping the file. The Files app has a Compress option that makes a zip archive. It works on documents. On video it does almost nothing, because video is already compressed and there are no repeated patterns left for zip to find. You get a file within a percent or two of the original, now harder to open.
A “video compressor” app that uploads your clip. Most of the compressor apps in the App Store, and nearly all of the websites, send your video to a server to process it. Apart from the privacy question, uploading a 400 MB file to shrink it defeats the purpose. Everything on this page runs on the phone, and so does iMovie.
If it is a dual camera recording
A dual camera video is one file at the resolution you chose, exactly like a single-camera clip, so every method above applies to it unchanged. The difference is that people tend to record these at 4K because both views are competing for pixels, which is also why the files are big. If you are recording a long take with both cameras, the settings in Method 4 matter more than the export in Method 1: drop to 1080p before you film, and you will not have to compress afterwards.