The AI arena is free today

Open Superagent

Claude Sonnet 4.6 vs Grok-4 Heavy

Grok-4 Heavy leads the LLM Stats Score 40.7 to 36.9.

Anthropic · xAI · Updated for 2026

Which is better?

Grok-4 Heavy leads the overall LLM Stats Score 40.7 to 36.9, ranking #61 overall.

The models split the 2 individual benchmarks reported for both models evenly.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Sonnet 4.6

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

Choose Grok-4 Heavy

  • overall performance matters — it scores 40.7 and ranks #61 on LLM Stats

At a glance

The differences that matter most.

Claude Sonnet 4.6
Anthropic
Grok-4 Heavy
xAI
Core performance indexes
LLM Stats Score
36.9
#78
40.7
#61
Reasoning
38.0
#70
39.0
#65
Coding
25.5
#76
17.7
#123
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
$3.00 / M
— / M
Output price
$15.00 / M
— / M
Context window
200,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Sonnet 4.6
Grok-4 Heavy
Math
34.4#49
41.5#7
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

17 reported for Claude Sonnet 4.6 · 6 for Grok-4 Heavy

2 shared

Claude Sonnet 4.6 outperforms in 1 benchmarks (GPQA), while Grok-4 Heavy is better at 1 benchmark (Humanity's Last Exam).

Both models are evenly matched across the benchmarks.

Mon Oct 05 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Sonnet 4.6 specifies input context (200,000 tokens). Only Claude Sonnet 4.6 specifies output context (64,000 tokens).

Anthropic
Claude Sonnet 4.6
Input200,000 tokens
Output64,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Mon Oct 05 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Sonnet 4.6 and Grok-4 Heavy support multimodal inputs.

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

Claude Sonnet 4.6

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 4.6

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4.6 was released on 2026-02-17, while Grok-4 Heavy's release date is not specified.

We can confirm Claude Sonnet 4.6's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Claude Sonnet 4.6

Feb 17, 2026

7 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 4.6'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 4.6's cutoff date.

Claude Sonnet 4.6

—

Grok-4 Heavy

Dec 2024

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Sonnet 4.6 and Grok-4 Heavy side-by-side, then vote on the output you prefer.

Claude Sonnet 4.6
✓ Preferred
Grok-4 Heavy
Open in Playground

FAQ

Common questions about Claude Sonnet 4.6 vs Grok-4 Heavy.

Which is better, Claude Sonnet 4.6 or Grok-4 Heavy?

Grok-4 Heavy leads the LLM Stats Score 40.7 to 36.9. Claude Sonnet 4.6 is made by Anthropic and Grok-4 Heavy is made by xAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Sonnet 4.6 compare to Grok-4 Heavy in benchmarks?

Claude Sonnet 4.6 scores Tau2 Telecom: 97.9%, Tau2 Retail: 91.7%, GPQA: 89.9%, MMMLU: 89.3%, SWE-Bench Verified: 79.6%. 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 Claude Sonnet 4.6 and Grok-4 Heavy?

Claude Sonnet 4.6 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.

What are the main differences between Claude Sonnet 4.6 and Grok-4 Heavy?

Key differences include LLM Stats Score (36.9 vs 40.7). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Sonnet 4.6 and Grok-4 Heavy?

Claude Sonnet 4.6 is developed by Anthropic and Grok-4 Heavy is developed by xAI.

Related comparisons