How to download iOS 26 on iPhone 15

Go to beta.apple.com, sign in with your Apple Account and follow the prompts, but remember that iOS 26 is not yet released, you'll be installing a beta version which might cause your device to be a bit slower or more error prone or the battery to last less.

You failed to mention the most important parts. Apple does not recommend that you should ever install the beta on a primary device needed for daily activities. Also if you choose to remove it, that will require a computer and you will have complete data loss unless you performed an archived backup first to a computer.

Go to beta.apple.com, sign in with your Apple Account and follow the prompts, but remember that iOS 26 is not yet released, you'll be installing a beta version which might cause your device to be a bit slower or more error prone or the battery to last less.

You might want to heed Apple's very strong advice to only install the beta software on a "spare" phone......not on a phone that you use everyday and need to be reliable.

It is amazing how many requests that we get on this site from users who have installed the beta software that are now asking how to remove it.

It is not available yet. Apple says it will be released some time this fall.