How to Fix When iOS 18 Not Installing: Top & Full Guide

The release of iOS 18 has brought a new user experience to many iPhone users. However, some users have encountered issues with installing the new system and found that iOS 18 cannot be installed properly. What could be the reason for this situation, and how can it be solved? Find answers in the following guidance!

Why iOS 18 not installing?

The issue can be caused by some reasons below.

How to fix iOS 18 not installing on new iPhone

Now you can get the solutions below to get how to fix the issue on your iPhone right now.

Solution 1. Check iPhone storage

Firstly, you can check your iPhone storage to confirm the details. Just go to Settings > General > Storage. You'll need at least 10 GB of free storage space to install them. 

Solution 2. Check network and battery level

iOS update can take dozens of minutes, so it needs a stable and strong Internet connection and at least 50% of battery level to download and install the iOS 18. So, we suggest you perform this process at home because usually the updating won't be interrupted by weak network/Wi-Fi or low battery level.

Please connect your iPhone with a charger if the battery level is low. And you can connect a Wi-Fi to make sure the network conditions, you can just go to the Settings app > Tap Wi-Fi > Choose a trusted and powerful Wi-Fi.

Solution 3. Check your device compatibility

iOS 18 only supports iPhone XR and later models / iPhone SE 2nd generation or later models. So if you are using an iPhone X or older model, then you can install iOS 18 successfully.

Solution 4. Best alternative way to update software 

If all of the ways above can't help you upgrade your iPhone to iOS 18 successfully, then you can use the professional iOS system repair software - FoneTool to update your iOS system in one click.

FoneTool

Powerful iOS system repair tool.

• Easily upgrade or downgrade the iOS system in 3 steps.
• Fast repairing speed allows you to finish the process in a very short time.
• Fix various iOS system issues, like frozen iPhone and black screen.
• Various iPhone models and iOS versions can be supported (iOS 18/iPhone 16).

Download Freeware
Windows 11/10/8/8.1/7

100% Secure

Now you can download FoneTool on your computer and learn from the steps below to update your iPhone to the latest iOS 18.

Step 1. Connect your iPhone to the computer > Launch FoneTool > Go to Toolbox > Choose iOS System Repair to continue.

Step 2. Choose iOS Upgrade/Downgrade.

Step 3. Go to the Upgrade section > Click Start.

Step 4. Choose the firmware version you need > Change the storage path from the Target Path option > Click Download to get the firmware.

Step 5. Once the download process is finished, just click Start Upgrade to begin the task.

Conclusion

Now you can know how to fix iOS 18 not installing on iPhone 15 or other older models. You can use 4 ways above to make it efficiently. And you must know that the professional iOS system repair software mentioned in Solution 4 might be the best way. With its powerful feature, you can also easily solve the iOS 18 beta update paused problem.

FoneTool - All-in-one iPhone Data Manager

Transfer, backup and manage data on iPhone, iPad and iPod touch in an easy way.

• iOS 18 Compatible
• iPhone 16 Supported

Download Freeware
Windows 11/10/8/8.1/7

100% Secure