A few days ago after updating the firmware of my Apple iPhone to iOS 10.2, I noticed that the storage capacity has decreased to 11.82 GB. As a result, I was getting the “Storage Almost Full” pop-up on my phone. I had only 0 kb of available storage. This is one of the nightmares of an owner of a 16 GB iPhone but there is a workaround for this.
In the iTunes library of my computer, most music files are in MP3 (MPEG-1 Audio Layer-3) format with a bit rate of 320 kbps. These consist of high quality audio and hence take up a lot of space if synced to an iPhone. For a compromise between file size and sound quality, all music files can be synced into the iPhone with AAC (Advanced Audio Coding) format. If you listen to an AAC audio file with a low bit rate (eg. 192 kbps), you can barely experience the difference in quality between that and an MP3 clip with 320 kbps bit rate, unlike an mp3 file with a low bit rate because the sound quality of an audio clip with a bit rate of 128 kbps will be very poor. However, I would not recommend AAC files with 128 kbps because the beats of certain songs cannot be heard the way they are meant to be heard.
Figure 1 : iTunes Window indicating the position of the check box which has to be ticked for conversion of audio files
Here’s how you can sync all your music files in AAC format with a low bit rate while keeping the audio files as they are in your computer:
- Open iTunes and connect the iPhone to the PC / Mac.
- Click on “iOS device” button on iTunes
- In Summary page, check “Convert higher bit rate songs to 128 kbps AAC” and select “192 kbps” from the drop-down menu.
- Finally, click “Sync”.
Here is a handy tip : You can gain some extra free space if you perform a Backup and Restore after syncing the music files in AAC format. More information on how to do this can be found in the following link : Storage: “I’m Out” !
I managed to get about 2.5 GB of free space after performing these procedures, thus making more room to install apps. Hope this helps.
You connect your Apple iPhone or iPad to your computer and open iTunes to sync some new music or to update the iOS version. On the storage row, you find that there’s an awful amount of “Other” storage, maybe even a bit more than 1 GB or even worse !
Figure 1 : “Other” storage on iPad or iPhone 
What is this “Other”? Other contains files that iTunes cannot categorise such as contacts, messages and emails. That’s not all. It can also contain corrupted files.
I am going to share how to reduce this “Other” storage and hopefully reclaim some of the lost storage in your iPhone or iPad. It is not necessary to restore your iOS device by downloading the most recent version of iOS. However, try it if the procedure given below fails.
- Connect your iOS device to the computer using the lightning connector (or USB cable for models before iPhone 5) and open iTunes
- Click on the “Device” icon (The one which looks like a phone) in iTunes.
- In order to avoid losing of your precious data that is stored in your iOS device, back it up to your computer by selecting “This computer” radio button under “Backups” and click on “Back Up Now”
- Disconnect your iOS device from the computer.
- In your iOS device, tap on Settings>General>Reset>Erase All Content and Settings and tap on “Erase iPhone” or “Erase iPad”. Wait for the iOS device to restart.
- When the Set Up screen gets displayed on your iOS device, connect your iOS device to the computer using the lightning connector (or USB cable) and open iTunes.
- Follow the steps given in this link to restore your iOS device : Restore your device from an iCloud or iTunes backup.
Notice that the “Other” storage has been significantly reduced and your lost free storage in your iOS device has been reclaimed.
Hope this helps.
 Stack Exchange. 2015. Ask Different. [ONLINE] Available at: http://i.stack.imgur.com/9hEZT.jpg. [Accessed 19 May 2016].