Distinguish device storage from iCloud storage
If you see a low-storage warning, first check where it appears. Storage inside your iPhone and iCloud storage are separate. Upgrading an iCloud plan does not increase the iPhone’s physical storage capacity. [2]
Check device storage in Settings → General → iPhone Storage. Review usage and the app list, and note whether photos or apps are the largest items to help decide where to start. Tap an app’s name to see its detailed usage and available management options. [1]
To check iCloud usage, open Settings → your name → iCloud. Even if the device has free space, a full iCloud account may prevent the iCloud features you use from staying up to date. Identifying which storage warning you have helps avoid repeating the wrong task. [2]
Menu locations can vary by operating system version, so check both the warning on the screen and your current version. Review usage and important files before choosing what to clear. There is no need to select and delete all your photos before checking storage.
Choose between Offload App and Delete App
Offload App frees the space used by the app itself while keeping its documents and data on the device. Delete App removes the app and its related data. If you may use the app again, read the explanation of both choices first. [1]
If documents and data occupy more space than the app itself, offloading alone may free less space than you expect. Check whether documents can be removed inside the app and whether you have kept needed files elsewhere. Before deleting, also review your login details and the material you want to retain. [1]
If recommendations appear on the storage screen, read them individually. Before enabling one, check which files it changes and distinguish items you can download again from those that are difficult to recreate. After managing one app, return to the usage screen to see the difference. [1]
Check photo storage optimization before deleting
If photos and videos account for a large share of storage, check whether you use iCloud Photos before deleting them. Storage optimization keeps full-resolution originals in iCloud and, when needed, smaller copies on your iPhone. [3]
Open Settings → your name → iCloud → Photos and review Sync this iPhone and the storage optimization options. Apple’s current English guide includes an iPhone Storage submenu for iOS 27 or later. Earlier versions may have a different layout, so look for the option names rather than assuming the same button sequence. [3]
You also need enough iCloud storage for the originals. Check available iCloud space as well as device space before changing the setting. Photos and videos you do not want to keep in iCloud can also be transferred to a computer. Verify that the transferred files actually open before clearing them from your iPhone. [3]
Check whether deleting photos affects other devices
Do not think of iCloud Photos as a separate archive that keeps cloud originals after you delete pictures on your iPhone. Deleting a photo or video on one device also deletes it on other devices connected to the same Apple Account. Back up anything you want to keep before deleting it. [4]
Deleted photos and videos generally remain recoverable in Recently Deleted for 30 days. Items permanently deleted from that album cannot be recovered, so check for pictures you still need before deleting everything to free space. [4]
If you have many similar photos, consider the merge feature in Duplicates. Apple says it is supported from iOS 16 onward, and automatic duplicate detection can take time. If the album does not appear immediately, check your version and the state of the library before manually deleting multiple pictures. [4]
Verify free space and important files afterward
Deleting apps and photos all at once makes it harder to see what occupied the space. Clear one large item, return to iPhone Storage to check the result, then choose the next item. If you need to save a photo or download a file, try that task again.
If you see System or Other, do not look for files with those names to delete in bulk. These categories include the operating system and various system files. Apple says the device manages cache and temporary files to free space, so you do not need to remove them yourself. [1]
If the problem continues, record the warning, device and iCloud usage separately, the names of large apps, and what you cleared. Giving usage figures for each screen helps support distinguish low iPhone storage from low iCloud storage.