How do I compress a video on iPhone?

Why is my iPhone video so big?

A video's size is its bitrate (how many bits each second of video gets) times its length:

Size in MB = bitrate in Mbps × seconds ÷ 8 (the ÷ 8 turns bits into bytes).

The bitrate goes up with resolution and frame rate. Apple puts it plainly: "Faster frame rates and higher resolutions result in larger video files" (Record a video with your iPhone camera). On the Pro models that record Apple ProRes, Apple adds that "ProRes videos result in larger file sizes" (Record ProRes video).

To see how big a clip is, open it in Photos and swipe up: the details include its file size (See photo and video information). Divide by the length to get its bitrate. For example, a 90-second clip of 300 MB runs at 300 × 8 ÷ 90 ≈ 26.7 Mbps. To fit Gmail's 25 MB, the same 90 seconds would need 25 × 8 ÷ 90 ≈ 2.2 Mbps for picture and sound together, about a twelfth of that.

Apple's iPhone pages give no bitrates, so the table uses YouTube's recommended upload bitrates as a yardstick:

Worked from the formula with 1 GB = 1,000 MB, picture only; sound at 128 kbps adds about 1 MB a minute. Real clips land either side, because the bitrate also depends on how much moves in the picture. Try your own numbers in the video bitrate calculator.

How do I make new iPhone videos smaller?

Change the camera settings before you record. They apply to new videos only, not to ones you already have.

1. Open Settings, tap Camera, tap Formats, then tap High Efficiency. Apple says HEIF and HEVC "offer better compression than JPEG and H.264, so they use less storage space" for the same visual quality; Most Compatible records H.264 instead, which plays on more devices (Using HEIF or HEVC media on Apple devices).
2. Go back to Camera, tap Record Video and pick a lower resolution or frame rate from the list, such as HD at 30 fps instead of 4K at 60 fps. The list depends on your model (Record a video).
3. For one clip only, open Camera, choose Video, and tap the resolution and frame rate values at the top of the screen to pick another format.
4. On a Pro model, leave Apple ProRes off (Settings ▸ Camera ▸ Formats) unless you need it.

How much does that save? 4K has four times the pixels of 1080p (3840 × 2160 against 1920 × 1080), and 60 fps has twice the frames of 30 fps. The bitrate doesn't grow exactly in step, but YouTube's table shows the scale: 8 Mbps for 1080p at 30 fps against 35–45 Mbps for 4K at 30 fps, so one minute is 8 × 60 ÷ 8 = 60 MB against 262.5–337.5 MB. Which to choose is covered in 720p vs 1080p vs 4K and 30 fps vs 60 fps.

How do I shrink a video that's already on my iPhone?

Trim it in Photos

A shorter clip at the same bitrate is a smaller file: a 3-minute clip trimmed to 1 minute is about a third of the size.

1. Open the video in Photos and tap the edit button.
2. Drag either end of the frame viewer below the video to set where it starts and stops, then tap Done.
3. Tap Save Video as New Clip to keep the original too, or Save Video to keep only the trimmed one. Apple notes that a video saved as a new clip can't be reverted to the original; a trimmed Save Video can be undone with Revert.

Source: Apple, Trim video length, adjust speed, and edit audio on iPhone.

Export a smaller copy from iMovie

Apple's iMovie app saves a new copy of a video at the resolution you choose.

1. In iMovie, tap Start New Project, then Movie. Select the video and tap Create Movie (Create a movie project).
2. Tap Done to leave the editor. In the Projects browser, tap the project, tap the Share button, then tap Share Video.
3. Tap Options and pick a lower resolution. Apple calls 1080p the best quality for most social media sites and says lower resolutions such as 720p HD make smaller files. Turn off HDR if the video will play on other devices: Apple advises it for the widest compatibility.
4. Tap Done, then Save Video to put the copy in your photo library.

Sources: Apple, Share your movie as a video file in iMovie on iPhone and Share or export your iMovie video. The copy is re-encoded, so it loses a little detail: keep the original until you've watched the copy.

How do I compress an iPhone video for email?

First check the limit. Personal Gmail accounts take 25 MB, and Gmail turns a bigger attachment into a Google Drive link (Gmail Help). Apple says the size limit for attachments is set by your service provider (Share photos and videos on iPhone). Then pick one of these:

• Send it with Mail Drop. In the Mail app, a file over your account's limit gets an onscreen offer to send it with Mail Drop (Add email attachments). Mail Drop takes attachments up to 5 GB, they don't count against your iCloud storage, and recipients have 30 days to download them (Mail Drop limits).
• Make a small copy in iMovie. Sharing to Mail from iMovie "creates a 360p-resolution video at 30 frames per second (fps), regardless of the original content", Apple says. That's small but soft; for a sharper copy, save a 720p version with the iMovie steps above and attach that.
• Trim it. A 25 MB message holds very little video: a 2-minute clip has to average 25 × 8 ÷ 120 ≈ 1.7 Mbps, picture and sound together. Sending only the part that matters helps more than any setting.

Every provider's limit is in email attachment size limits, and other ways to send big files are in how to compress a video for email.

How do I send a big iPhone video without compressing it?

Often the better answer is not to shrink it at all. Apple's guide to sharing long videos says some are too large for a standard text message and points to three ways round that:

• AirDrop, to a nearby iPhone, iPad, Mac or Apple Vision Pro, over Wi-Fi and Bluetooth. In Photos, open the video, tap the Share button, tap Options and turn on All Photos Data to send it in its original format, then tap AirDrop.
• iCloud. Sharing through iCloud Photos keeps a video's original format, resolution and frame rate (Using HEIF or HEVC media), and Apple's iMovie guide suggests an iCloud link or Mail Drop when you want to keep the highest resolution.
• Mail Drop, as above: up to 5 GB, downloadable for 30 days.

One catch: when you send by AirDrop, Messages or email to a device that doesn't support HEVC, Apple says the video might be sent in a more compatible format such as H.264. Sending to an Android phone has its own snags; see why iPhone videos won't play on Android.

Can I compress an iPhone video in a browser or on a computer?

Yes. Our free online video compressor reads MOV and MP4 files and saves a smaller MP4; the video is never uploaded, and its Target size setting aims for a size you choose in MB. iPhone videos in HEVC work when the browser can play HEVC itself. It is made for recent Chrome and Edge; Safari can compress too, more slowly, and sometimes stops part way. It does one video at a time, up to about 1–2 GB.

On a Mac, QuickTime Player's File ▸ Export As ▸ 720p or 480p saves a smaller copy as a .mov (Apple). The Mac, Windows and HandBrake steps are in how to shrink an MP4 and how to compress a MOV file.

If the video ends up on an Android phone, OctoZip compresses it there: pick the video, choose a Quick Compression preset (Small file, Medium file or Best Quality), tap Apply, then Start Compression. It works offline, never uploads the video, and is free to use with no ads. It runs on Android 7.0 or later.

GET IT ONGoogle Play

Does compressing an iPhone video lower its quality?

A little, whenever the video is re-encoded smaller: a lower resolution or bitrate holds less detail. Trimming cuts time, not bitrate. A clean lower resolution usually looks better than full resolution squeezed into too few bits, and each re-encode loses a bit more, so always start from the original. More in does compressing a video reduce quality? and can you compress a video twice?

What these ways can't do

• Apple's pages for the camera, iMovie and QuickTime list resolutions and frame rates, not a size in MB, so check the new size and step down if it's still too big.
• Camera settings change new videos only.
• Options depend on the iPhone model and iOS version, as Apple's pages say.
• We haven't measured sizes on an iPhone; every size on this page comes from the formula.

Sources

Checked on 3 November 2026.

• Apple: Using HEIF or HEVC media on Apple devices, Record a video, Record ProRes video, See photo and video information, Trim video length, Share long videos, Share photos and videos, Add email attachments, Mail Drop limits.
• Apple iMovie: Create a movie project, Share your movie as a video file, Share or export your iMovie video.
• Google: Gmail attachment limit, YouTube recommended upload encoding settings.

Related

• How do I compress a MOV file?
• How to shrink an MP4 (reduce MP4 file size)
• Why won't iPhone videos play on Android?
• Email attachment size limits
• HEVC vs H.264