I have plenty of available iCloud storage, automatic backups enabled, iCloud Photos set to Optimize iPhone Storage, and unused apps set to offload automatically. Even so, my iPhone keeps running out of local storage. Video recordings sometimes stop early, and I get warnings that I need to delete something before continuing. Photos are using about 11 GB, while the remaining space is mostly apps and their data. I deleted roughly 6,000 items and only have around 5 GB free, which fills up again quickly. Videos also often need to download before I can view or edit them. Coming from Android, I'm used to moving files to a computer or microSD card. Is there anything else I can do, and why doesn't iCloud automatically clear more space from the phone?
3 Answers
The fact that a video has to download before you edit it suggests iCloud Photos is working, but it still needs local space when recording, downloading, or editing. iOS also needs a reasonable amount of free working space, so 5 GB may not be enough for large videos. Check Recently Deleted in Photos and Files, since those can continue taking space until they are permanently removed. Also review the largest apps and their stored downloads; offloading an app does not necessarily remove all of its documents and data.
If the phone is consistently full after cleanup, the practical choices are to delete or move large videos to a computer or external drive, keep fewer local files, or use an iPhone with more built-in capacity. iCloud is useful for syncing and backup, but it is not an expandable drive like a microSD card. You can also check Settings > Photos to confirm that Sync this iPhone is complete and leave the phone on Wi-Fi and power so optimization has time to run.
iCloud storage and iPhone storage are separate. An iCloud backup is mainly a recovery copy; it does not automatically remove the original files from your phone. iCloud Photos can reduce local usage with Optimize iPhone Storage, but it keeps some originals or recently used files locally and may not immediately reclaim every possible gigabyte. Check Settings > General > iPhone Storage to see what is actually growing, especially Photos, Messages, Files, and app documents.

That helps clarify the distinction. Optimize Storage is already enabled, but Photos is still around 11 GB and the free space disappears again quickly after I delete things.