Model Comparison

GPT-4o vs Kimi-k1.5Which is better in 2026?

Kimi-k1.5 significantly outperforms across most benchmarks.

Verdict: GPT-4o vs Kimi-k1.5 — which is better?

GPT-4o (by OpenAI) and Kimi-k1.5 (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.

GPT-4o outperforms in 1 benchmarks (MMMU), while Kimi-k1.5 is better at 4 benchmarks (AIME 2024, IFEval, MathVista, MMLU). Kimi-k1.5 significantly outperforms across most benchmarks.

Choose GPT-4o if…

  • you want predictable pricing at $2.50/M input and $10.00/M output

Choose Kimi-k1.5 if…

  • you want the strongest raw capability — it leads on 4 of 5 shared benchmarks
  • you want the most recent training data — it shipped Jan 2025

Performance Benchmarks

Comparative analysis across standard metrics

5 benchmarks

GPT-4o outperforms in 1 benchmarks (MMMU), while Kimi-k1.5 is better at 4 benchmarks (AIME 2024, IFEval, MathVista, MMLU).

Kimi-k1.5 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 GPT-4o specifies input context (128,000 tokens). Only GPT-4o specifies output context (16,384 tokens).

OpenAI
GPT-4o
Input128,000 tokens
Output16,384 tokens
Moonshot AI
Kimi-k1.5
Input- tokens
Output- tokens
Sun Jul 05 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both GPT-4o and Kimi-k1.5 support multimodal inputs.

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

GPT-4o

Text
Images
Audio
Video

Kimi-k1.5

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.

GPT-4o

Proprietary

Closed source

Kimi-k1.5

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4o was released on 2024-08-06, while Kimi-k1.5 was released on 2025-01-20.

Kimi-k1.5 is 6 months newer than GPT-4o.

GPT-4o

Aug 6, 2024

1.9 years ago

Kimi-k1.5

Jan 20, 2025

1.5 years ago

5mo 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

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

OpenAI
Larger context window (128,000 tokens)
Higher MMMU score (72.2% vs 70.0%)
Moonshot AI
Higher AIME 2024 score (77.5% vs 13.1%)
Higher IFEval score (87.2% vs 81.0%)
Higher MathVista score (74.9% vs 61.4%)
Higher MMLU score (87.4% vs 85.7%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against GPT-4o and Kimi-k1.5 side-by-side, then vote on the output you prefer.

GPT-4o
✓ Preferred
Kimi-k1.5
Open in Playground
AI Model Comparison Table
Feature
OpenAI
GPT-4o
Moonshot AI
Kimi-k1.5

FAQ

Common questions about GPT-4o vs Kimi-k1.5.

Which is better, GPT-4o or Kimi-k1.5?

Kimi-k1.5 significantly outperforms across most benchmarks. GPT-4o is made by OpenAI and Kimi-k1.5 is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-4o compare to Kimi-k1.5 in benchmarks?

GPT-4o scores AI2D: 94.2%, DocVQA: 92.8%, ChartQA: 85.7%, MMLU: 85.7%, CharXiv-D: 85.3%. Kimi-k1.5 scores MATH-500: 96.2%, CLUEWSC: 91.4%, C-Eval: 88.3%, MMLU: 87.4%, IFEval: 87.2%.

What are the context window sizes for GPT-4o and Kimi-k1.5?

GPT-4o supports 128K tokens and Kimi-k1.5 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

Who makes GPT-4o and Kimi-k1.5?

GPT-4o is developed by OpenAI and Kimi-k1.5 is developed by Moonshot AI.

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