Model Comparison

Claude Sonnet 4 vs Grok-4 Heavy

Grok-4 Heavy significantly outperforms across most benchmarks.

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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Sonnet 4 outperforms in 0 benchmarks, while Grok-4 Heavy is better at 2 benchmarks (AIME 2025, GPQA).

Grok-4 Heavy significantly outperforms across most benchmarks.

Wed Apr 22 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
Wed Apr 22 2026 • llm-stats.com
Anthropic
Claude Sonnet 4
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
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 Claude Sonnet 4 specifies input context (200,000 tokens). Only Claude Sonnet 4 specifies output context (64,000 tokens).

Anthropic
Claude Sonnet 4
Input200,000 tokens
Output64,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Wed Apr 22 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

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

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

Claude Sonnet 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.

Claude Sonnet 4

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4 was released on 2025-05-22, while Grok-4 Heavy's release date is not specified.

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

Claude Sonnet 4

May 22, 2025

11 months ago

Grok-4 Heavy

—

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while Claude Sonnet 4's cutoff date is not specified.

We can confirm Grok-4 Heavy's training data extends to 2024-12-31, but cannot make a direct comparison without Claude Sonnet 4's cutoff date.

Claude Sonnet 4

—

Grok-4 Heavy

Dec 2024

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
xAI
Higher AIME 2025 score (100.0% vs 70.5%)
Higher GPQA score (88.4% vs 75.4%)
AnthropicClaude Sonnet 4
xAIGrok-4 Heavy
Compare in Playground

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Sonnet 4
xAI
Grok-4 Heavy

FAQ

Common questions about Claude Sonnet 4 vs Grok-4 Heavy

Grok-4 Heavy significantly outperforms across most benchmarks. Claude Sonnet 4 is made by Anthropic and Grok-4 Heavy is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Claude Sonnet 4 scores MMMLU: 86.5%, TAU-bench Retail: 80.5%, GPQA: 75.4%, MMMU: 74.4%, SWE-Bench Verified: 72.7%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.
Claude Sonnet 4 supports 200K 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.
Claude Sonnet 4 is developed by Anthropic and Grok-4 Heavy is developed by xAI.