Gemini 3 Deep Think

// Overview

Gemini 3 Deep Think is Google's extended-reasoning mode, released December 4, 2025. It is not a separate model but an optional inference-time setting on Gemini 3 Pro: per Google's official Gemini 3 Pro model card, "Gemini 3 Pro now features Deep Think mode, an optional setting designed to enhance complex problem-solving performance at time of inference." When enabled, the model spends much more compute exploring several lines of thought in parallel before it commits to an answer, which is why a single Deep Think response can take minutes rather than seconds.

Because Deep Think runs on the Gemini 3 Pro base, it inherits that model's natively multimodal design — it accepts text, images, audio, and video, with a context window of up to 1 million tokens and output up to 64K tokens. The underlying architecture is a sparse mixture-of-experts (MoE) transformer with a January 2025 knowledge cutoff. Deep Think is aimed squarely at the hardest tasks: graduate-level science, competition mathematics, multi-step logic, and abstract visual reasoning.

At launch, Gemini 3 Deep Think rolled out to Google AI Ultra subscribers in the Gemini app (selectable as the "Deep Think" thinking mode), with API access offered through an early-access program for select researchers, engineers, and enterprises rather than as a separately-priced public endpoint. It posts standout reasoning scores: 41.0% on Humanity's Last Exam without tools, 93.8% on GPQA Diamond, and an ARC-Prize-verified 45.1% on ARC-AGI-2 with code execution.

// Benchmarks

1. Humanity's Last Exam (no tools)41%
2. GPQA Diamond93.8%
3. ARC-AGI-2 (with code execution, ARC Prize Verified)45.1%

Scores on a 0–100 scale (25-point gridlines); higher is better. Each benchmark links to its published source.

// Pricing

At launch Gemini 3 Deep Think had no separately-published per-token API price; consumer access was via the Google AI Ultra plan ($249.99/mo) in the Gemini app, with API access through an early-access program. Standard Gemini 3 Pro API rates apply to the base model.

Pricing source ↗

// Strengths

• State-of-the-art abstract reasoning: 45.1% on ARC-AGI-2 (with code execution, ARC Prize Verified) — far above the standard Gemini 3 Pro result
• Top-tier graduate science knowledge: 93.8% on GPQA Diamond, ahead of Gemini 3 Pro's 91.9%
• Strong closed-book exam reasoning: 41.0% on Humanity's Last Exam with no tools
• Parallel-reasoning approach explores multiple hypotheses before answering, helping on hard math, physics, and logic problems
• Inherits the Gemini 3 Pro base: 1M-token context and native text/image/audio/video understanding
• Built for multi-step problem solving where extra inference-time compute pays off

// Best for

• Tackling competition-grade and research-level mathematics and proofs
• Graduate-level science questions in physics, chemistry, and related fields
• Abstract and visual reasoning puzzles that defeat standard chat models
• Reviewing technical or mathematical work to surface logical flaws
• Complex multi-step logic and planning problems
• Higher-quality code and prototypes for intricate, reasoning-heavy tasks

// How to access

// Gemini Deep Think — every version

The full lineage of the Gemini Deep Think line, newest first. Every version has its own page — click any to compare specs, benchmarks and pricing.