Delete unused apps
Offload unused apps
Remove large videos
Delete old photos and screenshots
Empty Recently Deleted in Photos
Clear Safari history and website data
Delete downloaded files
Remove old messages and attachments
Set Messages to keep fewer messages
Delete offline music, podcasts, and videos
Remove duplicate photos and videos
Review and delete large files in Files app
Clear app caches by reinstalling apps
Update iOS
Restart the iPhone
Check storage in Settings > General > iPhone Storage
Use iCloud Photos or other cloud storage
Back up and restore if storage remains full