iPhone storage full? What to delete first
Empty Recently Deleted, then large videos, duplicates, screenshots and message attachments. The order that frees the most iPhone space with the least regret.
Why can the same video take half the space?
While recording, your iPhone has to encode in real time, so it uses a high bitrate to be safe: around 50 Mbps for 4K at 60 fps, 8 to 10 Mbps for 1080p at 30 fps. Encoding the very same frames again with HEVC, without that time pressure, takes much less space at the same resolution.
What does DustFox change?
With the default Keep Quality setting, nothing but the encoding. Resolution, frame rate and HDR stay as they were. Two other settings exist for when you want a smaller file and accept a real loss: Balanced keeps the resolution and brings very high frame rates down to 60 fps, and Small Size caps the video at the resolution and frame rate you choose.
Which videos does it suggest?
Only the ones worth the effort. DustFox reads each video’s codec and bitrate and suggests it only if it can win at least a fifth of the file and at least 15 MB. Converting H.264 to HEVC frees real space; converting HEVC to HEVC mostly just spends quality, so those videos are skipped. A result that did not actually get smaller is never kept.
What happens to the original?
The smaller copy is added to your library, and after you confirm, the original moves to Recently Deleted for 30 days. The new copy does not stay in the albums the original was in, and on an edited video the “Revert to Original” option is gone. For a video you cannot replace, keep a backup first.
Does it run in the background?
On iOS 26, yes. The queue keeps going when you leave the app, with progress and a Stop control on the Lock Screen.
