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Gemini Deep Think

Last updated 2026-08-04 · Reviewed by ToolForge Editorial

Extended parallel reasoning for Google's Gemini flagship

★ 4.5 · Hundreds of millions (Gemini app) · Since 2025 (Google DeepMind) · Limited trial via AI Pro

$19.99 From $19.99/mo AI Pro (limited), $249.99/mo Ultra (full)

Try Gemini Deep Think → Read full review

Parallel thought-chains, scored on olympiad math

Gemini Deep Think is Google's extended-reasoning mode for the Gemini 2.5/3 family. Like Grok 4 Heavy, it evaluates multiple reasoning paths in parallel rather than committing to a single chain, then uses a scoring pass to select and synthesize. Google reports it performs at a gold-medal level on IMO-style mathematics and leads on benchmarks like Humanity's Last Exam and LiveCodeBench.

Who it's for: Quantitative researchers, olympiad-prep students, and Google-ecosystem teams who want top reasoning without leaving the Gemini UI.

Key features

Brain Parallel reasoning

Multiple simultaneous thought paths with a selection-and-scoring step before the final answer is assembled.

Trophy IMO gold level

Reported to solve 5 of 6 IMO 2025 problems under competition time, matching human gold-medal performance.

Layers Multimodal native

Images, audio, video, and PDFs can be dropped into the prompt and reasoned over without conversion.

Zap Integrated via Ultra

Available to Google AI Ultra subscribers ($249.99/mo tier) in the Gemini app and web UI, with$/rate limited daily.

The honest take

✓ What works

Gold-medal-class math and olympiad problem solving
Tightly integrated with Google's ecosystem (Search grounding, Workspace)
Strong long-context performance alongside 1M-token input windows
Much cheaper entry point than Grok 4 Heavy via AI Pro if you don't need full Heavy

✗ What doesn't

Deep Think is rate-limited even on Ultra — daily caps kick in quickly
Rollout was phased, so some regions/plans still don't see it in the app
Less transparent than Claude about chain-of-thought (summary only)
Hallucinations persist on niche factual topics despite grounding

Verdict

The best-reasoning-per-dollar of the heavy tiers, especially if you already pay for Google One.

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