Model Comparison

Claude Opus 4.5 vs Grok Code Fast 1

Claude Opus 4.5 significantly outperforms across most benchmarks. Grok Code Fast 1 is 19.0x cheaper per token.

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Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 4.5 outperforms in 1 benchmarks (SWE-Bench Verified), while Grok Code Fast 1 is better at 0 benchmarks.

Claude Opus 4.5 significantly outperforms across most benchmarks.

Fri May 08 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok Code Fast 1 costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 25.0x more expensive than Grok Code Fast 1 ($0.20/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 16.7x more expensive than Grok Code Fast 1 ($1.50/1M tokens).

In conclusion, Claude Opus 4.5 is more expensive than Grok Code Fast 1.*

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

Lowest available price from all providers
Fri May 08 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
xAI
Grok Code Fast 1
Input tokens$0.20
Output tokens$1.50
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok Code Fast 1 accepts 256,000 input tokens compared to Claude Opus 4.5's 200,000 tokens. Claude Opus 4.5 can generate longer responses up to 64,000 tokens, while Grok Code Fast 1 is limited to 10,000 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
xAI
Grok Code Fast 1
Input256,000 tokens
Output10,000 tokens
Fri May 08 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 4.5 supports multimodal inputs, whereas Grok Code Fast 1 does not.

Claude Opus 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 4.5

Text
Images
Audio
Video

Grok Code Fast 1

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 Opus 4.5

Proprietary

Closed source

Grok Code Fast 1

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Grok Code Fast 1 was released on 2025-08-28.

Claude Opus 4.5 is 3 months newer than Grok Code Fast 1.

Claude Opus 4.5

Nov 24, 2025

5 months ago

2mo newer
Grok Code Fast 1

Aug 28, 2025

8 months ago

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Grok Code Fast 1's cutoff date is not specified.

We can confirm Claude Opus 4.5's training data extends to 2025-03-31, but cannot make a direct comparison without Grok Code Fast 1's cutoff date.

Claude Opus 4.5

Mar 2025

Grok Code Fast 1

—

Provider Availability

Claude Opus 4.5 is available from Anthropic. Grok Code Fast 1 is available from xAI.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

Grok Code Fast 1

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $1.50/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

Anthropic
Supports multimodal inputs
Higher SWE-Bench Verified score (80.9% vs 70.8%)
xAI
Larger context window (256,000 tokens)
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
xAI
Grok Code Fast 1

FAQ

Common questions about Claude Opus 4.5 vs Grok Code Fast 1.

Which is better, Claude Opus 4.5 or Grok Code Fast 1?

Claude Opus 4.5 significantly outperforms across most benchmarks. Claude Opus 4.5 is made by Anthropic and Grok Code Fast 1 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to Grok Code Fast 1 in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. Grok Code Fast 1 scores SWE-Bench Verified: 70.8%.

Is Claude Opus 4.5 cheaper than Grok Code Fast 1?

Grok Code Fast 1 is 25.0x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. Grok Code Fast 1 costs $0.20/M input and $1.50/M output via xai.

What are the context window sizes for Claude Opus 4.5 and Grok Code Fast 1?

Claude Opus 4.5 supports 200K tokens and Grok Code Fast 1 supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 4.5 and Grok Code Fast 1?

Key differences include context window (200K vs 256K), input pricing ($5.00 vs $0.20/M), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and Grok Code Fast 1?

Claude Opus 4.5 is developed by Anthropic and Grok Code Fast 1 is developed by xAI.