Apple Replaces Siri's Brain with Google Gemini — And Lets You Swap In Claude or ChatGPT

Apple's WWDC 2026 keynote on June 8 confirmed what leaks had been telegraphing for months: Siri's default AI brain is now Google Gemini, and for the first time in Apple's history, users will be able to swap in a competing AI model instead.

The Gemini Deal

Apple and Google have signed a multi-year deal — reportedly worth around $1 billion per year — that places Gemini at the core of Siri's reasoning and generation capabilities. The arrangement follows Apple's earlier deal with OpenAI for ChatGPT integration in iOS 18 and 18.1, but this time the integration goes deeper. Gemini doesn't just answer overflow queries; it powers Siri's own responses by default.

For Google, the deal puts its model on approximately 1.4 billion active iPhones. For Apple, it offloads the hardest part of frontier AI — training and running state-of-the-art large models — to a partner while retaining control of the user experience and the privacy layer that processes personal context on-device.

Extensions: Choosing Your AI

The more surprising announcement is the Extensions system. In iOS 27, iPadOS 27, and macOS 27, users can open Settings → Apple Intelligence & Siri and select which model handles their AI queries: Gemini (the new default), ChatGPT, or Anthropic's Claude. More providers are expected to follow before the September launch.

When a third-party model handles a Siri query, it speaks in a different voice — distinct from Apple's own Siri voice — so users hear, not just read, which AI is responding. Apple framed this as a transparency feature: you always know whether you're talking to Apple's system or an outside provider.

Developer betas of iOS 27 shipped the afternoon of the keynote. Public betas are expected in mid-July, with the full release in September alongside the new iPhone lineup.

What This Changes

Until now, the dominant AI distribution channel has been the chatbot interface — a browser tab or a standalone app. WWDC 2026 shifts that. The AI you use for daily tasks is now a system-level choice baked into the operating system of the most popular smartphone on earth. Anthropic and OpenAI don't just compete for users who seek out their apps; they now compete for the setting a user toggles once and forgets.

For Claude specifically, this is the first time Anthropic's model has been available as a first-class option on an Apple device. The Extension system is effectively an AI distribution deal disguised as a settings menu.

The practical implication is also straightforward: if you've been using ChatGPT because it was the only non-default option on your iPhone, you now have a choice. If you've been avoiding AI assistants because the only options felt wrong, you now have a settings toggle to try something different.