Model Comparison

Grok-1.5 vs Kimi K2 0905Which is better in 2026?

Kimi K2 0905 significantly outperforms across most benchmarks.

Verdict: Grok-1.5 vs Kimi K2 0905 — which is better?

Grok-1.5 (by xAI) and Kimi K2 0905 (by Moonshot AI) 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 Kimi K2 0905 is better at 5 benchmarks (GPQA, HumanEval, MATH, MMLU, MMLU-Pro). Kimi K2 0905 significantly outperforms across most benchmarks.

Choose Grok-1.5 if…

  • you are already invested in the xAI ecosystem

Choose Kimi K2 0905 if…

  • you want the strongest raw capability — it leads on 5 of 5 shared benchmarks
  • you want the most recent training data — it shipped Sep 2025
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Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

Grok-1.5 outperforms in 0 benchmarks, while Kimi K2 0905 is better at 5 benchmarks (GPQA, HumanEval, MATH, MMLU, MMLU-Pro).

Kimi K2 0905 significantly outperforms across most benchmarks.

Tue Jun 09 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Kimi K2 0905 specifies input context (262,144 tokens). Only Kimi K2 0905 specifies output context (262,144 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
Moonshot AI
Kimi K2 0905
Input262,144 tokens
Output262,144 tokens
Tue Jun 09 2026 • llm-stats.com

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

Kimi K2 0905

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while Kimi K2 0905 was released on 2025-09-05.

Kimi K2 0905 is 18 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.2 years ago

Kimi K2 0905

Sep 5, 2025

9 months ago

1.4yr 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

xAI

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

Moonshot AI
Larger context window (262,144 tokens)
Higher GPQA score (75.8% vs 35.9%)
Higher HumanEval score (94.5% vs 74.1%)
Higher MATH score (89.1% vs 50.6%)
Higher MMLU score (90.2% vs 81.3%)
Higher MMLU-Pro score (82.5% vs 51.0%)

Detailed Comparison

AI Model Comparison Table
Feature
xAI
Grok-1.5
Moonshot AI
Kimi K2 0905

FAQ

Common questions about Grok-1.5 vs Kimi K2 0905.

Which is better, Grok-1.5 or Kimi K2 0905?

Kimi K2 0905 significantly outperforms across most benchmarks. Grok-1.5 is made by xAI and Kimi K2 0905 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-1.5 compare to Kimi K2 0905 in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. Kimi K2 0905 scores HumanEval: 94.5%, MMLU: 90.2%, MATH: 89.1%, MMLU-Pro: 82.5%, GPQA: 75.8%.

What are the context window sizes for Grok-1.5 and Kimi K2 0905?

Grok-1.5 supports an unknown number of tokens and Kimi K2 0905 supports 262K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes Grok-1.5 and Kimi K2 0905?

Grok-1.5 is developed by xAI and Kimi K2 0905 is developed by Moonshot AI.

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