Work through these checks in order
Check which categories actually use the most space instead of deleting randomly.
Before removing photos, messages or files, confirm that anything important exists somewhere else.
Downloads, large videos you no longer need, offline media, duplicate files and unused apps are common places to start.
Some apps can safely clear temporary data; others may remove offline files or require sign-in again.
Aim for enough free space to complete updates and normal app operations rather than waiting until the device is completely full.
Before an erase, restore or repair decision
Confirm what data is backed up, what a reset or restore will remove, and whether you still need access to account credentials or authentication methods stored on the device.
When professional service makes sense
Hardware damage, repeated power failure, liquid exposure, battery swelling, damaged ports, broken displays and problems that persist after low-risk software checks can require qualified inspection.