One of the most common questions I get from readers on a regular basis is something along the lines of, "What the heck is this Other storage category and why is it eating so much storage space?" If that sounds like something you've said to yourself, you certainly aren't alone. As it turns out, there's a few explanations for the mysterious Other storage issue, as well as a way you can keep it under control!
What is the "Other storage" label on my iPhone or iPad actually storing?
While it would be nice to know exactly where all our storage space is going, there are just too many things that require physical storage that labeling all of them would result in a bar that stretched much father than what your computer screen would allow. That's why Apple chose to lump a lot of things into the "Other" category. Basically, the Other category consists of anything that doesn't have a Home in another label.
However, these are some of the important things that are contained in the Other category —
Documents & Data
Safari browsing data
Mail data such as cached files
iTunes Match and iTunes in the Cloud cached data (I'm kind of guessing on this one)
While some of the above items are mainly stored in iCloud, like Documents & Data, I'm almost positive some of it is stored locally so if you don't have an internet connection, you can access information for the time being. For example, you can access your Numbers spreadsheets and iCloud will just wait to sync them until your internet connection is live again.
But what if I have several gigabytes of data being taken up by "Other storage"?
This isn't an uncommon scenario and one that I've experienced myself a time or two. The most common cause is corrupt files that can't be removed by iOS. These kinds of files can build up over time, resulting in a significant loss of storage space.
For example, if you never do a clean restore in iOS and you continually restore from iCloud every time you get a new device, you could potentially bring over corrupt files from many installs. Think about that for a minute. That could add up to tons of gigabytes of lost storage space.
How to free up some of the "Other storage" on your iPhone or iPad
If you have less than 1 GB of "Other storage" on your device, that is about normal for most folks and you can probably leave it be. However, if you have more than that, it's worth trying to recapture the lost space.
In order to do so, the most effective way is an iTunes backup and restore. Since iTunes actually removes all files off of your iPhone or iPad and then places new copies back on, it can clear up corrupt file issues and remove bad backup files.
This process is different from iCloud since iCloud restores, updates, and backups only make incremental changes. So in order to re-capture space, you'll want to do the following, in this order —
Back up your iPhone or iPad to iTunes.
Restore your iPhone or iPad with iTunes.
Restore from the iTunes backup you made in Step 1.
That's it! Once you're backup is done restoring from iTunes, check out your storage capacity again and see if it's any different. Most folks are able to free up at least 1GB, if not more in many cases. And for those of you with 16 GB or smaller devices, a few GB can make a huge difference.
Give it a try and let me know what your results are in the comments!