Model Comparison

Claude Opus 4.5 vs Grok-4.20 Beta ReasoningWhich is better in 2026?

Comparing Claude Opus 4.5 and Grok-4.20 Beta Reasoning across benchmarks, pricing, and capabilities.

Verdict: Claude Opus 4.5 vs Grok-4.20 Beta Reasoning — which is better?

Claude Opus 4.5 (by Anthropic) and Grok-4.20 Beta Reasoning (by xAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

On price, Grok-4.20 Beta Reasoning is roughly 3.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Grok-4.20 Beta Reasoning also accepts a larger context window (2,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 4.5 if…

  • you want predictable pricing at $5.00/M input and $25.00/M output

Choose Grok-4.20 Beta Reasoning if…

  • cost matters — it's about 3.3x cheaper per token
  • you process long inputs — it offers a 2,000,000 token context window
  • you want the most recent training data — it shipped Mar 2026
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Claude Opus 4.5 and Grok-4.20 Beta Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok-4.20 Beta Reasoning costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 2.5x more expensive than Grok-4.20 Beta Reasoning ($2.00/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 4.2x more expensive than Grok-4.20 Beta Reasoning ($6.00/1M tokens).

In conclusion, Claude Opus 4.5 is more expensive than Grok-4.20 Beta Reasoning.*

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

Lowest available price from all providers
Sat Jun 13 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
xAI
Grok-4.20 Beta Reasoning
Input tokens$2.00
Output tokens$6.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok-4.20 Beta Reasoning accepts 2,000,000 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-4.20 Beta Reasoning is limited to 30,000 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
xAI
Grok-4.20 Beta Reasoning
Input2,000,000 tokens
Output30,000 tokens
Sat Jun 13 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.5 and Grok-4.20 Beta Reasoning support multimodal inputs.

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

Claude Opus 4.5

Text
Images
Audio
Video

Grok-4.20 Beta Reasoning

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-4.20 Beta Reasoning

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Grok-4.20 Beta Reasoning was released on 2026-03-09.

Grok-4.20 Beta Reasoning is 4 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

6 months ago

Grok-4.20 Beta Reasoning

Mar 9, 2026

3 months ago

3mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Grok-4.20 Beta Reasoning'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-4.20 Beta Reasoning's cutoff date.

Claude Opus 4.5

Mar 2025

Grok-4.20 Beta Reasoning

—

Provider Availability

Claude Opus 4.5 is available from Anthropic. Grok-4.20 Beta Reasoning is available from xAI.

Claude Opus 4.5

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

Grok-4.20 Beta Reasoning

xai logo
xAI
Input Price:Input: $2.00/1MOutput Price:Output: $6.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Anthropic

No standout differentiators in the data we have for this pair.

xAI
Larger context window (2,000,000 tokens)
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
xAI
Grok-4.20 Beta Reasoning

FAQ

Common questions about Claude Opus 4.5 vs Grok-4.20 Beta Reasoning.

Which is better, Claude Opus 4.5 or Grok-4.20 Beta Reasoning?

Claude Opus 4.5 (Anthropic) and Grok-4.20 Beta Reasoning (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Claude Opus 4.5 compare to Grok-4.20 Beta Reasoning 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%.

Is Claude Opus 4.5 cheaper than Grok-4.20 Beta Reasoning?

Grok-4.20 Beta Reasoning is 2.5x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. Grok-4.20 Beta Reasoning costs $2.00/M input and $6.00/M output via xai.

What are the context window sizes for Claude Opus 4.5 and Grok-4.20 Beta Reasoning?

Claude Opus 4.5 supports 200K tokens and Grok-4.20 Beta Reasoning supports 2.0M 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-4.20 Beta Reasoning?

Key differences include context window (200K vs 2.0M), input pricing ($5.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and Grok-4.20 Beta Reasoning?

Claude Opus 4.5 is developed by Anthropic and Grok-4.20 Beta Reasoning is developed by xAI.

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