Apple is always working a few releases ahead internally, so it comes as no surprise that web logs are already showing signs of devices running iOS 26.4 visiting websites.
iOS 26.4 spotted in web logs
iOS 26.4 spotted in web logs
The iOS 26 release cycle is under heavy scrutiny after Apple failed to deliver a promised more contextual Apple Intelligence and Siri. The iOS 26.4 release seems to be carrying a lot of weight features-wise, so it makes sense for testing to start as early as possible.
According to website visitor logs at MacRumors, there are already devices testing iOS 26.4. Nothing can be gleaned from these logs, of course, other than the operating system existing on a device that visited the website.