One of the plus points of iOS is that support for older devices goes back several years and generations, versus Android in which usually OEMs end support after 2-3 years tops. For example iOS 11 supports devices as old as the iPhone 5s which was released back in 2013, 5 years ago.
Now chances are there probably aren’t that many people still using the iPhone 5s, but if there are, the good news is that iOS 12 could continue to support your device. This is according to development testing reports for WebKit where it mentions support for the iPhone 5s. This was initially discovered by MacGeneration.
This would be an interesting turn of events because for the past several years, every major iOS update has seen support dropped for at least one model. For example iOS 10 stopped supporting the iPhone 4s which was the last supported model for iOS 9. With the release of iOS 11, the iPhone 5 and iPhone 5c were no longer supported, which is why it is largely assumed that with iOS 12, support for the iPhone 5s would be dropped as well.
We should point out that none of this has been set in stone just yet which means that there is still a chance the iPhone 5s might no longer be supported in iOS 12. However like we said, chances are there aren’t too many iPhone 5s handsets out there these days anyway, so it probably won’t be too big of an impact either way.