iOS Ref

iOS version by device

iPhone

Device Released First iOS Max iOS
iPhone X 2017 11 12 Beta
iPhone 8 / 8 Plus
iPhone 7 / 7 Plus 2016 10
iPhone SE 9
iPhone 6s / 6s Plus 2015
iPhone 6 / 6 Plus 2014 8
iPhone 5s 2013 7
iPhone 5c 10
iPhone 5 2012 6
iPhone 4s 2011 5 9
iPhone 4 2010 4 7
iPhone 3GS 2009 3 6
iPhone 3G 2008 2 4
iPhone (gen 1) 2007 1 3

iPad

Device Released First iOS Max iOS
iPad (gen 6) 2018 11 12 Beta
iPad Pro 12.9" (gen 2) 2017 10
iPad Pro 10.5"
iPad (gen 5)
iPad Pro 9.7" 2016 9
iPad Pro 12.9" (gen 1) 2015
iPad mini 4
iPad mini 3 2014 8
iPad Air 2
iPad mini 2 2013 7
iPad Air (gen 1)
iPad (gen 4) 2012 6 10
iPad mini (gen 1) 9
iPad (gen 3) 5 9
iPad 2 2011 4
iPad (gen 1) 2010 3 5

iPod touch

Device Released First iOS Max iOS
iPod touch (gen 6) 2015 8 12 Beta
iPod touch (gen 5) 2012 6 9
iPod touch (gen 4) 2010 4 6
iPod touch (gen 3) 2009 3 5
iPod touch (gen 2) 2008 2 4
iPod touch (gen 1) 2007 1 3