Why is my iPhone 6s downloading iOS 15.8 but not installing it?

My iPhone 6s can’t install iOS version 15.8.1 after downloaded, anytime I tried it will show error occurred.

If you still can't install the latest version of iOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.
2. Find the iOS update in the list of apps.
3. Tap the iOS update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest iOS update.

If you don’t see the update in the list of apps or if the issue happens again, you need to update your device with iTunes.

Try updating iOS after each step.

• Try to Forget the WiFi network and add it again
• Try another WiFi network 
• Toggle sets automatically off and then on
• Reset your network settings
• Force restart your device
• Remove any beta profiles, if applicable

• If everything fails: - Use iTunes or Finder (for macOS Catalina+) to update your device instead of over-the-air
• Get help with iOS updates and restore errors - Apple Support
• If you see an error when you update or restore your iPhone, iPad

iPhone 6s can receive important updates. Apple released iOS 15.8 specifically for older devices to address security concerns. To update your iPhone 6s to iOS 15.8:

1. Go to Settings > General > Software Update.

2. Download and install iOS 15.8 to keep your device secure.

When Can iPhone 6s Get iOS 18?

Unfortunately, the iPhone 6s and similar models, including the iPhone SE, iPhone 7, and their Plus versions, will not receive iOS 18 or 17. Apple's announcement highlights the natural progression of technology, where older devices eventually fall behind as new advancements are made.

All information about iOS 15.8.1

[Edited by Moderator]

Since all of them are repeatedly answering with the same answer that won't solve the issue. Try clear some storage from your phone, even though there is 2-3 Gbs of storage left, it's still not enough for the install, try clear more and retry until it gets through. The install apparently will require more than the said install file size. I cleared up 6-7 Gbs and it went through.

It can be that you have insufficient storage available to unpack and prepare the update. It appears that you need around 6GB of free storage to process and install 15.8.1, more than previously. It should work if you can free up at least this space, or you can try installing the update by connecting to a Mac/PC and install from there.

An iPhone 6/6 plus can't be updated beyond 12.5.7, it doesn't have the hardware required to run anything higher.

If you need a higher iOS version, you will have to purchase a newer phone.

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.7

• If you have an iPhone 6S through 7, or SE 1st generation, you can update to 15.8.2

• If you have an iPhone 8 or X, you can update to 16.7.7

• If you have an iPhone SE (2nd generation or later), or XR through 15, you can update to 17.5.1

Ubanka1 wrote:

What’s the solution

The solution to what?

You cannot update an iPhone 6 or 6 Plus to iOS 13 or higher. iOS 12 is the end of the line.

You cannot update an iPhone 6s or 6s Plus to iOS 16 or higher. iOS 15 is the end of the line.

If you are having trouble updating your iPhone to the latest release of the latest major version of iOS that it supports, see

Updating iOS: common issues and solutions - Apple Community

If the issue is that you have an old iPhone and want to run apps that are incompatible with it, the solution is to replace the old iPhone with a more up-to-date iPhone.

Can you post a screenshot of the whole screen, it could reveal why you aren't able to update.

Make sure you:

• Are using a WiFi connection (not a hotspot).

• You have an active cell signal (You need both WiFi and cellular service to perform the upgrade).

• Are not using a VPN connection.

• Have your battery charged at least 50%. Better yet, keep it plugged in during the update.

• Do not have power save mode turned on.

• Do not have a beta version installed.

• You have at least 10 gigs of storage available.

Click on this link on what to do if you can't update your phone -

If your iPhone or iPad won't update – Apple Support (UK)

Please Help me download to iOS 15

Tell us the problem in detail.

Which device or model are you using now?

An iPhone 6 can't be updated beyond 12.5.7, it doesn't have the hardware required to run anything higher.

If you need a higher iOS version, you will have to purchase a newer phone.

• If you have an iPhone 5S or 6/6plus, the highest you can update to is 12.5.7

• If you have an iPhone 6S through 7, or SE 1st generation, you can update to 15.8.2

• If you have an iPhone 8 or X, you can update to 16.7.7

• If you have an iPhone SE (2nd generation or later), or XR through 15, you can update to 17.5.1

When I click on software update there no buttons but at the bottom it says my iPhone will try to install it later tonight and I clicked on it and it said it has to be charged and connected to WiFi and it was and nothing happened so I wanna know how to make it download today!

My iPhone 6s can’t install iOS version 15.8 after downloaded

My iPhone 6s can’t install iOS version 15.8 after I downloaded version 15.8. I can download but I can’t install only.

When I click on install button , this occurs verifying update and then unable to install update caption with this letter “an error occurred installing ios15.8.”

what should I do?

pls help me or give me some advice.

https://discussions.apple.com/thread/254246579?&previousThread=255286333021