Model Comparison

Grok-4 vs Grok-4 HeavyWhich is better in 2026?

Grok-4 Heavy significantly outperforms across most benchmarks.

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

Grok-4 (by xAI) 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.

Grok-4 outperforms in 0 benchmarks, while Grok-4 Heavy is better at 6 benchmarks (AIME 2025, GPQA, HMMT25, Humanity's Last Exam, LiveCodeBench, USAMO25). Grok-4 Heavy significantly outperforms across most benchmarks.

Choose Grok-4 if…

  • you want predictable pricing at $3.00/M input and $15.00/M output

Choose Grok-4 Heavy if…

  • you want the strongest raw capability — it leads on 6 of 6 shared benchmarks
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

Grok-4 outperforms in 0 benchmarks, while Grok-4 Heavy is better at 6 benchmarks (AIME 2025, GPQA, HMMT25, Humanity's Last Exam, LiveCodeBench, USAMO25).

Grok-4 Heavy significantly outperforms across most benchmarks.

Thu Jun 11 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Grok-4 specifies input context (256,000 tokens). Only Grok-4 specifies output context (8,000 tokens).

xAI
Grok-4
Input256,000 tokens
Output8,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Thu Jun 11 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Grok-4 and Grok-4 Heavy support multimodal inputs.

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

Grok-4

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.

Grok-4

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-4 was released on 2025-07-09, while Grok-4 Heavy's release date is not specified.

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

Grok-4

Jul 9, 2025

11 months ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Both models have the same knowledge cutoff date of 2024-12-31.

They should have similar awareness of historical events and information up to this date.

Grok-4

Dec 2024

Grok-4 Heavy

Dec 2024

Outputs Comparison

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Key Takeaways

xAI
Larger context window (256,000 tokens)
xAI
Higher AIME 2025 score (100.0% vs 91.7%)
Higher GPQA score (88.4% vs 87.5%)
Higher HMMT25 score (96.7% vs 90.0%)
Higher Humanity's Last Exam score (50.7% vs 40.0%)
Higher LiveCodeBench score (79.4% vs 79.0%)
Higher USAMO25 score (61.9% vs 37.5%)
xAIGrok-4
xAIGrok-4 Heavy
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Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-4
xAI
Grok-4 Heavy

FAQ

Common questions about Grok-4 vs Grok-4 Heavy.

Which is better, Grok-4 or Grok-4 Heavy?

Grok-4 Heavy significantly outperforms across most benchmarks. Grok-4 is made by xAI 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 Grok-4 compare to Grok-4 Heavy in benchmarks?

Grok-4 scores AIME 2025: 91.7%, HMMT25: 90.0%, GPQA: 87.5%, LiveCodeBench: 79.0%, Humanity's Last Exam: 40.0%. 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 Grok-4 and Grok-4 Heavy?

Grok-4 supports 256K 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.

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