How to Compress a Video on iPhone: Settings, Trimming, and Sharing

iPhones record beautiful video, and that quality is exactly why the files are so large. If your storage keeps filling up, or clips refuse to send in messaging apps and email, there are two places to fix it: the Camera settings that decide how big new videos are, and compression for the videos you already have.

Why iPhone videos are so large

The iPhone shows its own estimates under Settings, Camera, Record Video. Using the High Efficiency format, one minute takes roughly:

Exact numbers vary by model and iOS version, and the Most Compatible (H.264) format roughly doubles them. ProRes and Log recording on Pro models are far larger again, often several gigabytes per minute. Compare these numbers to a 16 MB WhatsApp limit or a 20 MB email limit and the problem is obvious.

Step 1: record smaller files from the start

1. 1Open Settings, then Camera, then Formats, and choose High Efficiency. This records HEVC (H.265), which is about half the size of Most Compatible (H.264) at the same quality.
2. 2In Settings, Camera, Record Video, choose 1080p at 30 fps for everyday clips. Switch to 4K only for footage you will edit or watch on a big screen.
3. 3On Pro models, leave ProRes and Log off unless you are editing professionally.

Recording at 1080p/30 instead of 4K/60 cuts the size per minute by more than six times, and on a phone screen most people cannot tell the difference.

Step 2: trim in the Photos app

1. 1Open the video in Photos and tap Edit.
2. 2Drag the yellow handles at either end of the timeline to keep only what you need.
3. 3Tap Done, then choose Save Video as New Clip to keep the original, or Save Video to replace it.

Trimming is the only way to reduce size with zero quality loss, so always do it first.

Step 3: compress the clip

Open the BoltCompress compressor in Safari, tap the upload area, and choose the video from your library. The tool shows an estimated size for each level before you start. High Efficiency is a good default for iPhone footage. When it finishes, tap Download and the file goes to the Files app (Downloads folder), from where you can share it or save it to Photos.

Make a 1080p copy of a 4K video

BoltCompress keeps the original resolution. To downscale on the phone, use iMovie (free from Apple): create a movie, add the clip, tap Done, then tap the share icon and pick 1080p or 720p in the export options before saving. Compress that copy afterwards if it still needs to be smaller.

Sharing without compressing at all

• •AirDrop sends the original file to nearby Apple devices with no size limit and no quality loss.
• •Mail Drop sends attachments up to 5 GB from the Mail app as an iCloud link that lasts 30 days.
• •An iCloud link (Photos, Share, Copy iCloud Link) lets anyone view the full quality original.
• •Messages re-compresses video sent to Android phones, so compress it yourself first for a cleaner result.

Free up storage without deleting memories

If storage is the problem rather than sharing, turn on Optimize iPhone Storage (Settings, your name, iCloud, Photos). Full resolution originals stay in iCloud and the phone keeps smaller versions. For videos you keep outside iCloud, compressing old 4K clips with High Efficiency usually halves them.

Summary

Record in High Efficiency at 1080p/30 for everyday clips, trim in Photos, and compress before sharing anything long. For apps with strict limits, check our upload limits page and the WhatsApp guide.