Model Comparison

Claude 3 Opus vs Grok-1.5Which is better in 2026?

Claude 3 Opus significantly outperforms across most benchmarks.

Verdict: Claude 3 Opus vs Grok-1.5 — which is better?

Claude 3 Opus (by Anthropic) and Grok-1.5 (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.

Claude 3 Opus outperforms in 6 benchmarks (GPQA, GSM8k, HumanEval, MATH, MMLU, MMLU-Pro), while Grok-1.5 is better at 0 benchmarks. Claude 3 Opus significantly outperforms across most benchmarks.

Choose Claude 3 Opus if…

  • you want the strongest raw capability — it leads on 6 of 6 shared benchmarks

Choose Grok-1.5 if…

  • you want the most recent training data — it shipped Mar 2024
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Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

Claude 3 Opus outperforms in 6 benchmarks (GPQA, GSM8k, HumanEval, MATH, MMLU, MMLU-Pro), while Grok-1.5 is better at 0 benchmarks.

Claude 3 Opus significantly outperforms across most benchmarks.

Mon Jun 15 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Claude 3 Opus specifies input context (200,000 tokens). Only Claude 3 Opus specifies output context (200,000 tokens).

Anthropic
Claude 3 Opus
Input200,000 tokens
Output200,000 tokens
xAI
Grok-1.5
Input- tokens
Output- tokens
Mon Jun 15 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude 3 Opus supports multimodal inputs, whereas Grok-1.5 does not.

Claude 3 Opus can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude 3 Opus

Text
Images
Audio
Video

Grok-1.5

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 3 Opus

Proprietary

Closed source

Grok-1.5

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3 Opus was released on 2024-02-29, while Grok-1.5 was released on 2024-03-28.

Grok-1.5 is 1 month newer than Claude 3 Opus.

Claude 3 Opus

Feb 29, 2024

2.3 years ago

Grok-1.5

Mar 28, 2024

2.2 years ago

4w newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
Supports multimodal inputs
Higher GPQA score (50.4% vs 35.9%)
Higher GSM8k score (95.0% vs 90.0%)
Higher HumanEval score (84.9% vs 74.1%)
Higher MATH score (60.1% vs 50.6%)
Higher MMLU score (86.8% vs 81.3%)
Higher MMLU-Pro score (68.5% vs 51.0%)
xAI

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

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude 3 Opus
xAI
Grok-1.5

FAQ

Common questions about Claude 3 Opus vs Grok-1.5.

Which is better, Claude 3 Opus or Grok-1.5?

Claude 3 Opus significantly outperforms across most benchmarks. Claude 3 Opus is made by Anthropic and Grok-1.5 is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude 3 Opus compare to Grok-1.5 in benchmarks?

Claude 3 Opus scores ARC-C: 96.4%, HellaSwag: 95.4%, GSM8k: 95.0%, MGSM: 90.7%, BIG-Bench Hard: 86.8%. Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%.

What are the context window sizes for Claude 3 Opus and Grok-1.5?

Claude 3 Opus supports 200K tokens and Grok-1.5 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 3 Opus and Grok-1.5?

Key differences include multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude 3 Opus and Grok-1.5?

Claude 3 Opus is developed by Anthropic and Grok-1.5 is developed by xAI.

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