What changes on September 4

Google has set September 4, 2026 as the date Google Assistant stops working across most consumer hardware: Android phones, Android tablets, Wear OS smartwatches, supported headphones and earbuds, and Android Auto sessions projected from a phone. Saying "Hey Google" or long-pressing the power button on any of these devices will launch Gemini, not Assistant. Google has told users directly by email that the change is coming, and the same message now appears as a banner across the Google Assistant support pages: Gemini is replacing Google Assistant on most mobile devices, and there is no setting to switch back once a device has been migrated.

The removal is not instant for every device on the same morning. Google is rolling the change out in stages over several weeks, so two people with the same phone model may see the switch land days apart. The practical effect for anyone budgeting a migration is the same either way: treat September 4 as the start of the window, not a single hard cutoff, and assume the transition completes within roughly a month after that.

The exemption: cars with Google built-in

One category is explicitly carved out of this round. Vehicles with embedded "Google built-in" infotainment - where Android runs natively in the dashboard rather than being projected from a phone - keep Google Assistant for now, on a timeline Google has not announced. That distinction matters for fleet operators and automotive partners: a car that mirrors a phone through Android Auto loses Assistant on the same schedule as the phone itself, while a car with Google's software baked into the head unit does not move yet.

Google TV, Google Home speakers, smart displays and other non-mobile surfaces are also outside this specific wave. Gemini is expected to reach them eventually, but no date has been set, which means any integration built around those device classes is not yet under the same four-week clock as phones, tablets, wearables and Android Auto.

The migration checklist for EU and UK businesses

Any organisation with a live Assistant-based integration should treat the next four weeks as a hard deadline, not a planning window. Four groups are directly exposed. First, smart-home and proptech vendors that shipped "Ask Google Assistant to..." voice routines for lighting, heating or access control in EU and UK homes and hotels need those routines re-tested against Gemini's voice command surface, since Gemini does not guarantee identical phrase-matching behaviour to the old Assistant NLU stack. Second, automotive suppliers and aftermarket integrators building voice features for Android Auto - as opposed to embedded Google built-in systems - lose their current voice layer on the same September 4 schedule as consumer phones, with no separate grace period. Third, hospitality and retail operators running voice kiosks, in-room assistants or customer-facing Android tablets that call Assistant need a Gemini-based replacement validated before the device-level cutover reaches their hardware batch, given the staged rollout means not all units flip on the same day. Fourth, developers who built on the Assistant SDK or Actions on Google - the developer platform, not the consumer app - should confirm directly with Google's developer documentation whether their integration path is affected, since the API-level deprecation timeline for Actions on Google is a separate question from the consumer-device shutdown described here and has not been detailed in the same announcement.

The common failure mode is assuming Assistant will keep working until it visibly breaks. Because the rollout is staged over weeks, a business that tests only its own office device on September 4 may pass, then find customer-facing units fail two or three weeks later when their turn in the rollout arrives. The safer approach is to assume every Assistant-dependent device in a fleet needs independent verification against Gemini before the end of September, rather than relying on one spot-check.