If your device is low on storage, iOS optimizes the storage while doing things like installing an app, updating the iOS, downloading music, recording videos, and more. To create more storage, iOS removes some of your items, like streamed music and videos, and parts of apps that aren't needed. It also removes temporary files and clears the cache on your device. iOS only removes items that can be downloaded again or that aren't needed anymore.
Use your iOS device to check its storage
Go to Settings > General > Storage & iCloud Usage > Manage Storage.
You'll see a list of your apps, and how much storage each one uses. For more information about its usage, tap the app from the list. Cached data and temporary data might not be counted as usage.
Depending on the app, you might be able to delete some of its content, or delete the app and all of its content. If your device is almost full and iOS can't free up space on your device, you might get a Storage Almost Full alert. If you see this alert you'll need to remove some less-used content yourself.
Use iTunes to check the storage on your iOS device
- Open iTunes on your computer.
- Connect your device to your computer.
- In iTunes, select your device. You'll see a bar that shows how much storage your iOS content uses, divided by content type.
- Move your mouse over a content type, like Other or Apps, to find more information:
Here is a list of the types of content on your iOS device, and what each type includes:
- Audio: Songs, audio podcasts, audiobooks, voice memos, and ringtones
- Video: Movies, music videos, and TV shows
- Photos: Camera Roll content, Photo Stream, and Photo Library
- Apps: Installed apps. The content of the apps is listed under Documents & Data.
- Books: iBooks books, audio books, and PDF files
- Documents & Data: Safari Offline Reading List, files stored within installed apps, and app content like contacts, calendars, messages, and emails (and their attachments)
- Other: Settings, Siri voices, system data, and cached files
About cached files in "Other" iOS storage
Cached files are created when streaming or viewing content like music, videos, and photos. When you stream music or video, that content is stored as cached files on your iOS device so you can quickly access it again. iTunes categorizes cached music, videos, and photos as Other instead of actual songs, videos, or photos.
Your iOS device automatically removes cached files and temporary files when your device needs more space.
If storage on an iOS device differs from what you see in iTunes
Since iTunes categorizes cached files as Other, reported usage for Music or Videos might differ. To view usage on your iOS device, go to Settings > General > Usage > Manage Storage.
If you want to delete the cached files from your iOS device
Your iOS device automatically deletes cached files and temporary files when it needs more space. You don't need to delete them yourself.
- To reduce the size of your Photo library, turn on iCloud Photo Library and optimize your device storage.
- Learn about storage capacity on OS X and iOS.