Google has started replacing its Google Assistant with a new AI tool called Gemini on Android smartphones and tablets, beginning in early September 2026. This change means that users on affected devices can no longer switch back to Google Assistant through the settings menu. Instead, a long press on the power button or swiping from a corner of the screen now activates Gemini. Reports indicate that the option to switch back was removed in the stable version 17.60 and beta version 17.62 of the Google app on devices in the United States and Europe. This update ends the ability to choose between assistants through the account menu, making Gemini the only available option on these devices. The transition to Gemini was originally planned for 2025 but was delayed until 2026. However, the change appears to have been moved forward, with Google sending emails to users warning them about the update. The migration affects not only smartphones but also connected devices like Wear OS watches, headphones, headsets, and Android Auto systems. Vehicles with built-in Google systems are not included in this wave of updates. Meanwhile, Google Assistant is still available on devices like Google Nest and Google Home speakers and screens, as well as on Google TV, which are not affected by this change. Users who previously relied on switching between assistants when a command didn't work as expected now lose that option on migrated devices. However, users with older smartphones or those in regions where Gemini is not yet supported can still use Google Assistant. Google has not provided a clear timeline for when the transition will occur on these remaining devices. The shift to Gemini includes new features beyond traditional voice commands, such as managing calls, messages, timers, and interactions with other apps. The removal of the ability to switch back makes the change more noticeable, as users on updated devices can no longer access the previous functionality. This update reflects Google’s broader strategy to unify its AI capabilities under a single platform. While Gemini offers expanded features, the lack of a fallback option may present challenges for users who are not yet comfortable with the new system. Google has not indicated when or if the ability to switch back might be reintroduced in the future.