Model Comparison

Gemini 3 Flash vs Grok-4 HeavyWhich is better in 2026?

Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Verdict: Gemini 3 Flash vs Grok-4 Heavy — which is better?

Gemini 3 Flash (by Google) and Grok-4 Heavy (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Gemini 3 Flash outperforms in 1 benchmarks (GPQA), while Grok-4 Heavy is better at 2 benchmarks (AIME 2025, Humanity's Last Exam). Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Choose Gemini 3 Flash if…

  • you want predictable pricing at $0.50/M input and $3.00/M output

Choose Grok-4 Heavy if…

  • you want the strongest raw capability — it leads on 2 of 3 shared benchmarks
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Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Gemini 3 Flash outperforms in 1 benchmarks (GPQA), while Grok-4 Heavy is better at 2 benchmarks (AIME 2025, Humanity's Last Exam).

Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Sun Jun 07 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Gemini 3 Flash specifies input context (1,000,000 tokens). Only Gemini 3 Flash specifies output context (65,536 tokens).

Google
Gemini 3 Flash
Input1,000,000 tokens
Output65,536 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Sun Jun 07 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3 Flash and Grok-4 Heavy support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3 Flash

Text
Images
Audio
Video

Grok-4 Heavy

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 3 Flash

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3 Flash was released on 2025-12-17, while Grok-4 Heavy's release date is not specified.

We can confirm Gemini 3 Flash's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Gemini 3 Flash

Dec 17, 2025

5 months ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Gemini 3 Flash has a knowledge cutoff of 2025-01-31, while Grok-4 Heavy has a cutoff of 2024-12-31.

Gemini 3 Flash has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to Grok-4 Heavy (2024-12-31).

Gemini 3 Flash

Jan 2025

1 mo newer
Grok-4 Heavy

Dec 2024

Outputs Comparison

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Key Takeaways

Google
Larger context window (1,000,000 tokens)
Higher GPQA score (90.4% vs 88.4%)
xAI
Higher AIME 2025 score (100.0% vs 99.7%)
Higher Humanity's Last Exam score (50.7% vs 43.5%)

Detailed Comparison

AI Model Comparison Table
Feature
Google
Gemini 3 Flash
xAI
Grok-4 Heavy

FAQ

Common questions about Gemini 3 Flash vs Grok-4 Heavy.

Which is better, Gemini 3 Flash or Grok-4 Heavy?

Grok-4 Heavy shows notably better performance in the majority of benchmarks. Gemini 3 Flash is made by Google and Grok-4 Heavy is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Gemini 3 Flash compare to Grok-4 Heavy in benchmarks?

Gemini 3 Flash scores Vending-Bench 2: 100.0%, AIME 2025: 99.7%, Global PIQA: 92.8%, MMMLU: 91.8%, GPQA: 90.4%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.

What are the context window sizes for Gemini 3 Flash and Grok-4 Heavy?

Gemini 3 Flash supports 1.0M tokens and Grok-4 Heavy supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes Gemini 3 Flash and Grok-4 Heavy?

Gemini 3 Flash is developed by Google and Grok-4 Heavy is developed by xAI.

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