Model Comparison

Grok-4 vs Grok-4 Heavy

Grok-4 Heavy significantly outperforms across most benchmarks.

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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.

Mon Apr 27 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Cost data unavailable.

Lowest available price from all providers
Mon Apr 27 2026 • llm-stats.com
xAI
Grok-4
Input tokens$3.00
Output tokens$15.00
Best providerxAI
xAI
Grok-4 Heavy
Input tokens$0.00
Output tokens$0.00
Best providerUnknown Organization
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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
Mon Apr 27 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

9 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

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.
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%.
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.