Gemini 3 Deep Think by Google
Google · Coding · Other
Gemini 3 Deep Think is Google's most advanced AI reasoning mode, built to tackle hard math, science and logic problems that trip up standard models. It works inside the Gemini app, where it explores multiple lines of thinking at once instead of committing to a single answer path. The catch is access: Deep Think is reserved for Google AI Ultra subscribers at $249.99 a month.
About Gemini 3 Deep Think by Google
What Is Gemini 3 Deep Think
Gemini 3 Deep Think is a reasoning mode layered on top of the Gemini 3 Pro model. Google built it for problems where a quick answer isn't good enough, like competition-level math, scientific analysis, and multi-step logic puzzles. According to Google, it leads on rigorous benchmarks such as Humanity's Last Exam at 41.0% without tools and ARC-AGI-2 at 45.1% with code execution.
The idea behind Deep Think is parallel reasoning. Instead of generating one chain of thought, the model explores several hypotheses at the same time, compares them, and settles on the strongest path that fits the evidence it has gathered along the way. That's a lot more compute per answer, which is why it takes longer than a normal reply. For a hard problem, the wait is usually worth it. For a simple question, it's overkill.
The biggest limitation is the paywall. Deep Think isn't a free feature and it isn't sold on its own. You need a Google AI Ultra plan, and Ultra also bundles Veo, higher Gemini usage limits and 30TB of Google storage, so you're paying for the whole package rather than just this one mode.
Getting Started
- Subscribe to Google AI Ultra in your Google account.
- Open the Gemini app on the web or on your phone and sign in with that account.
- Pick Gemini 3 Pro from the model dropdown.
- Select "Deep Think" in the prompt bar.
- Type your problem and wait while the mode works through multiple reasoning paths.
Product Information
A quick look at Gemini 3 Deep Think by Google's pricing, supported platforms, and performance.
Best for
The users, tasks, and scenarios where this tool fits best.
Users
- Researchers and graduate students
- Competitive programmers and puzzle solvers
- Curious power users
Tasks
- Working through olympiad-style math problems
- Checking a scientific claim step by step
- Debugging a tricky algorithm
- Stress-testing an argument
Scenarios
- A late-night problem set that a standard chatbot keeps getting wrong
- Reviewing a research draft for logical gaps
- A one-off hard question you don't mind waiting on
Key features
Parallel Hypothesis Exploration
Deep Think doesn't follow one line of reasoning to the end. It explores several hypotheses at once, weighs them against each other, and picks the path that holds up best. That's the core of why it does better on problems with many possible starting points.
Benchmark-Leading Reasoning
According to Google, Deep Think scores 41.0% on Humanity's Last Exam without tools and 45.1% on ARC-AGI-2 with code execution. Those are vendor-reported numbers, but they put the mode at the front of the pack for hard reasoning tests. Google also reports 93.8% on the GPQA Diamond science benchmark.
Built Into the Gemini App
You don't install anything separate. Deep Think sits inside the Gemini app on web, Android and iOS, selectable from the prompt bar alongside the Gemini 3 Pro model. That keeps it in the same place you already chat with Gemini.
Code Execution
On ARC-AGI-2, Deep Think can run code as part of solving a problem rather than reasoning about it in the abstract, which lets it check an idea against real output instead of trusting a hunch. For programming and logic tasks, that means it can test an approach and adjust instead of guessing. Big difference.
Longer Thinking Time
The mode spends more time on each answer than a standard Gemini reply. That extra time is the point: Google says it lets the model refine and combine ideas before committing. Expect slower responses on complex inputs and roughly normal speed on easy ones.
Ultra-Only Access
Deep Think ships as part of the Google AI Ultra subscription. There's no standalone purchase and no free tier, so the price of entry is the full Ultra plan at $249.99 a month.
Pros and cons
Pros
- Leads on several hard reasoning benchmarks, per Google's own figures.
- Parallel reasoning suits problems where a single chain of thought goes wrong.
- Lives inside the Gemini app, so there's no separate tool to learn.
- Code execution makes it more useful for programming and logic tasks.
- Bundled with the rest of Google AI Ultra, including Veo and 30TB of storage.
Cons
- Costs $249.99 a month with no cheaper way to get just this mode.
- No public API, so you can't call Deep Think from your own app.
- Slower than a normal Gemini reply, which makes it a poor fit for quick questions.
- The benchmark wins are vendor-reported and mostly target math, science and logic rather than everyday tasks.
Frequently asked questions
It's a reasoning mode on top of Gemini 3 Pro that explores many hypotheses at once to solve difficult math, science and logic problems. You turn it on inside the Gemini app rather than using it as a separate product. So how do you actually use it? Pick Gemini 3 Pro, then switch Deep Think on.
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