Is it possible to update iPhone 8 to iOS 17?

No, sorry, iOS 16.7.12 is the highest you can go on an iPhone 8

• 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 15.8.5

• If you have an iPhone 8 or X, you can update to 16.7.12

• If you have an iPhone SE (2nd generation or later), or XR through 16, you can update to 26.0.1

Kurtosis12 wrote:

If you have an iPhone SE (2nd generation or later), or XR through 16, you can update to 26.0.1

Small correction - iPhone XR/XS can only update to iOS 18.7. iPhone SE (2nd or 3rd generation) and iPhone 11 or newer can update to iOS 26.0.1.

in the real world it is the app providers and particularly the banks who dictate when our phones become obsolete.