Can’t Download iOS Update: Not Enough Free Space
A lot of users got stuck when Apple released the iOS 8 system update. Why did they run into trouble? Well, the typical issue was: “I can’t download the iOS update, there is not enough free space”. Confusingly, the affected users thought that they had enough free storage space and had verified this as a matter of fact in their “Settings” app or via iTunes.
iOS 8.0 update/upgrade woes
Especially owners of 16 GB iPhones tend to run into trouble with iOS updates, as the actual system updates require more storage to install “OTA” (over-the-air) than the download is taking up. Thus one GB of spare space often will not suffice, as the update will try to unpack and install itself. The error message then goes by “requires at least X GB of storage”.
For instance, the update to iOS 8.0 on our test device took a whopping 4.7 GB to install on an iPhone. That is more than a fourth of the available storage space on the smallest version of the newer iPhone devices. Naturally, a lot of users simply did not have that much empty space on their internal iPhone storage. The update installer suggested to delete a few items from the iPhone, but we deemed that an unsatisfactory solution.
Our solution: Update via iTunes instead of OTA
Connect your iPhone via USB cable to a PC or Mac running the latest version of iTunes. Select your iPhone from the device overview (small iPhone icon) and let iTunes search for an update for your device. Usually, you will already be prompted automatically, after the initial sync. If not, select “Check for Update” or “Update”. Updating via iTunes does not require the extra space the OTA method reserves for file operations and should thus be possible with a minimum of unoccupied storage. Enjoy!