New apps will not work. Device features will be slower. And most importantly, the latest security updates will not be applied.
If you have an iPhone 5c or earlier model you will have to update your device. If not, you will be risking your data’s security and be left behind in new apps.
iOS 11 will work on:
- iPhone 5s, 6, 6plus, 6s, 6s plus, SE, 7 and 7 plus
- iPad Air and Air 2, iPad mini 2, 3, 4, fifth gen iPad and all iPad Pros
- 6th gen iPod touch