Gemini 3 Deep Think: how it works and how to turn it on

Google has switched on Deep Think for Gemini 3 inside the Gemini app—designed for tougher, multi-step problems where you need deliberation over speed. Ultra subscribers can enable it from the model selector. blog.google

What Deep Think changes

Deep Think asks Gemini 3 to reason more deliberately before responding, which helps with synthesis, planning, code refactors, and step-wise analyses.

How to turn it on (quick steps)

1. Open the Gemini app

2. Pick Gemini 3 Pro

3. Tap Deep Think in the prompt bar

4. Ask a complex, context-rich question.

Where it’s available

Gemini 3 Pro is rolling out across the Gemini app and AI Mode in more countries; Ultra (and in some posts Pro) subscribers get higher limits and early features. Check your plan and region in the app.

Use cases for UK teams

• Quarterly planning and trade-off analysis

• Policy comparisons and decision logs

• Code review and refactoring plans

• Risk registers and mitigation options

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FAQ

Is Deep Think free?
No. It’s available in the Gemini app for Ultra subscribers when using Gemini 3 Pro. blog.google

How do I enable it?
Select Gemini 3 Pro, then turn on Deep Think in the prompt bar. blog.google

Does it work in AI Mode?
Gemini 3 features are expanding in AI Mode across more countries; check your region and plan. blog.google