Model Comparison

Grok-1.5 vs Claude 3 OpusWhich is better in 2026?

Claude 3 Opus significantly outperforms across most benchmarks.

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

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

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

Choose Grok-1.5 if…

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

Choose Claude 3 Opus if…

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

Performance Benchmarks

Comparative analysis across standard metrics

6 benchmarks

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

Claude 3 Opus significantly outperforms across most benchmarks.

Sun Jul 05 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).

xAI
Grok-1.5
Input- tokens
Output- tokens
Anthropic
Claude 3 Opus
Input200,000 tokens
Output200,000 tokens
Sun Jul 05 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.

Grok-1.5

Text
Images
Audio
Video

Claude 3 Opus

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.

Grok-1.5

Proprietary

Closed source

Claude 3 Opus

Proprietary

Closed source

Release Timeline

When each model was launched

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

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

Grok-1.5

Mar 28, 2024

2.3 years ago

4w newer
Claude 3 Opus

Feb 29, 2024

2.3 years ago

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

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI

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

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%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok-1.5 and Claude 3 Opus side-by-side, then vote on the output you prefer.

Grok-1.5
✓ Preferred
Claude 3 Opus
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok-1.5
Anthropic
Claude 3 Opus

FAQ

Common questions about Grok-1.5 vs Claude 3 Opus.

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

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

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

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

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

Grok-1.5 supports an unknown number of tokens and Claude 3 Opus supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-1.5 and Claude 3 Opus?

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

Who makes Grok-1.5 and Claude 3 Opus?

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

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