How to lower video quality
on iPhone and save space.

1. Lower the video resolution or frame rate

1. Open Settings › Camera › Record Video.
2. Pick a resolution and frame rate. The options depend on your iPhone model.
3. Read the list under the options: it shows what a minute of video takes at each setting.

In High Efficiency, Apple's figures for a minute of video are about 40 MB at 720p HD and 30 fps, 60 MB at 1080p HD and 30 fps, 90 MB at 1080p HD and 60 fps, 135 MB at 4K and 24 fps, 170 MB at 4K and 30 fps, and 400 MB at 4K and 60 fps.

2. Keep High Efficiency on

Settings › Camera › Formats offers High Efficiency (HEIF photos, HEVC video) and Most Compatible (JPEG and H.264). High Efficiency gives the same quality in less space: a minute of 4K at 30 fps is about 170 MB, against about 350 MB in Most Compatible.

3. HDR video and Auto FPS

HDR Video, in Settings › Camera › Record Video on supported models, makes files a little larger: about 65 MB a minute instead of 60 MB at 1080p and 30 fps, and 190 MB instead of 170 MB at 4K and 30 fps. Auto FPS lowers the frame rate to 24 fps in low light to improve the picture. It is a quality setting, so leave it on.

4. ProRAW and ProRes

Both are for editing and both are large. A ProRAW photo is about 25 MB at 12 MP and about 75 MB at 48 MP, where a High Efficiency photo is about 2 MB at 12 MP. A minute of ProRes is about 1.7 GB at 1080p and 30 fps and about 6 GB at 4K and 30 fps. On models that have them, turn them off under Settings › Camera › Formats.

5. Photo resolution and Live Photo

On supported models, Settings › Camera › Formats › Photo Mode switches between 24 MP and 12 MP: about 3 MB a photo against about 2 MB in High Efficiency. Live Photo stores a short video with every picture. To keep it off, turn it off in Camera, then turn on Live Photo under Settings › Camera › Preserve Settings so the choice sticks.

Videos you already recorded

These settings only change what you record from now on. To make an existing video smaller, compress it.

Step 1 of 6Already recorded? On the Clean tab, the Videos card shows what your videos take: 27.4 GB. Tap it.

Step 2 of 6The largest videos come first, each with its size. Tap the ones to compress.

Step 3 of 6Three picked, 19.7 GB in all: compressing them saves about 9.85 GB. Tap Compress Selected.

Step 4 of 6Three levels: Low saves about 20%, Medium about 50%, High about 70%. At Medium, with Keep originals off, 19.7 GB becomes about 9.85 GB and each original is replaced. Tap Compress 3 videos.

Step 5 of 6It compresses on your iPhone. Nothing is replaced until every video is ready; then iOS asks you to confirm once.

Step 6 of 63 videos compressed: the library is 9.85 GB smaller. The originals wait in Recently Deleted, and the space comes back when you empty it, or after 30 days.