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Model Comparison

Claude Sonnet 4.5 vs Grok-4

Grok-4 significantly outperforms across most benchmarks. Claude Sonnet 4.5 and Grok-4 cost the same.

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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Sonnet 4.5 outperforms in 0 benchmarks, while Grok-4 is better at 2 benchmarks (AIME 2025, GPQA).

Grok-4 significantly outperforms across most benchmarks.

Thu Apr 23 2026 • llm-stats.com

Arena Performance

Human preference votes

CallingBox

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$0.05 /min all-in7 lines of code

Pricing Analysis

Price comparison per million tokens

Grok-4 costs less

For input processing, Claude Sonnet 4.5 ($3.00/1M tokens) costs the same as Grok-4 ($3.00/1M tokens).

For output processing, Claude Sonnet 4.5 ($15.00/1M tokens) costs the same as Grok-4 ($15.00/1M tokens).

In conclusion, Claude Sonnet 4.5 and Grok-4 cost the same.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Apr 23 2026 • llm-stats.com
Anthropic
Claude Sonnet 4.5
Input tokens$3.00
Output tokens$15.00
Best providerAnthropic
xAI
Grok-4
Input tokens$3.00
Output tokens$15.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok-4 accepts 256,000 input tokens compared to Claude Sonnet 4.5's 200,000 tokens. Claude Sonnet 4.5 can generate longer responses up to 64,000 tokens, while Grok-4 is limited to 8,000 tokens.

Anthropic
Claude Sonnet 4.5
Input200,000 tokens
Output64,000 tokens
xAI
Grok-4
Input256,000 tokens
Output8,000 tokens
Thu Apr 23 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Sonnet 4.5 and Grok-4 support multimodal inputs.

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

Claude Sonnet 4.5

Text
Images
Audio
Video

Grok-4

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 4.5

Proprietary

Closed source

Grok-4

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Sonnet 4.5 was released on 2025-09-29, while Grok-4 was released on 2025-07-09.

Claude Sonnet 4.5 is 3 months newer than Grok-4.

Claude Sonnet 4.5

Sep 29, 2025

6 months ago

2mo newer
Grok-4

Jul 9, 2025

9 months ago

Knowledge Cutoff

When training data ends

Claude Sonnet 4.5 has a knowledge cutoff of 2025-01-31, while Grok-4 has a cutoff of 2024-12-31.

Claude Sonnet 4.5 has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to Grok-4 (2024-12-31).

Claude Sonnet 4.5

Jan 2025

1 mo newer
Grok-4

Dec 2024

Provider Availability

Claude Sonnet 4.5 is available from Anthropic. Grok-4 is available from xAI.

Claude Sonnet 4.5

anthropic logo
Anthropic
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M

Grok-4

xai logo
xAI
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Anthropic
xAI
Larger context window (256,000 tokens)
Higher AIME 2025 score (91.7% vs 87.0%)
Higher GPQA score (87.5% vs 83.4%)
AnthropicClaude Sonnet 4.5
xAIGrok-4
Compare in Playground

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Sonnet 4.5
xAI
Grok-4

FAQ

Common questions about Claude Sonnet 4.5 vs Grok-4

Grok-4 significantly outperforms across most benchmarks. Claude Sonnet 4.5 is made by Anthropic and Grok-4 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.
Claude Sonnet 4.5 scores MMMLU: 89.1%, AIME 2025: 87.0%, TAU-bench Retail: 86.2%, GPQA: 83.4%, MMMUval: 77.8%. Grok-4 scores AIME 2025: 91.7%, HMMT25: 90.0%, GPQA: 87.5%, LiveCodeBench: 79.0%, Humanity's Last Exam: 40.0%.
Both models cost $3.00 per million input tokens.
Claude Sonnet 4.5 supports 200K tokens and Grok-4 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (200K vs 256K). See the full comparison above for benchmark-by-benchmark results.
Claude Sonnet 4.5 is developed by Anthropic and Grok-4 is developed by xAI.