iOS Ref

iOS version by device

iPhone

Device Released First iOS Max iOS
iPhone 11 Pro / 11 Pro Max 2019 13 13
iPhone 11
iPhone XS / XS Max 2018 12
iPhone XR
iPhone X 2017 11
iPhone 8 / 8 Plus
iPhone 7 / 7 Plus 2016 10
iPhone SE 9
iPhone 6s / 6s Plus 2015
iPhone 6 / 6 Plus 2014 8 12
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

See iPadOS version by device.

iPod touch

Device Released First iOS Max iOS
iPod touch (gen 7) 2019 12 13
iPod touch (gen 6) 2015 8 12
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