Other storage taking up 15GB?!?
Tip: To see more files that are using space on your device, open your Settings app Storage Files a folder. Android phones and tablets can fill up quickly as you download apps, add media files like music and movies, and cache data for use offline.
How to clean up Android devices and other storage - Syncios
If not custom Rom then don't apply in this case. Basically, some gaming apps and messaging apps like WhatsApp may save much gaming data or chat record which takes up large space, and that's what we usually see the "Other" storage when analyzing the storage. Settings Storage Cached data, then tap, oK in the confirmation window. But wait, theres more: tapping the Files option at the bottom will let you take a look at your storage in a more categorized view, very similar to Android devices running Nougat or older. Clear out all cached app data.
Five Ways to Free Up Space on Your Android Device - HowToGeek
Yes, no, i need help. Make sure you have the latest version of iTunes, have backed up the device, and have synced content with your computer. You can check how much space your offline maps have staked out by tapping the three-line menu button in the top left corner of the main Google Maps interface, then tap, offline. Possible Preventative Solutions, nip the full-memory problem in the bud next time around.
How to See What s Taking Up Space on Your Android Device
Open the app drawer and tap Downloads to see whats lurking in the Downloads folder. From there, tap on into the Device Maintenance menu. It will immediately start running the device maintenance checklist, but you can pretty much ignore thatjust tap on Storage at the bottom. Check your image/video storage space. Tap on each one to see whats filling up space in each category.