Model Comparison

GPT-4.1 vs Kimi K2 BaseWhich is better in 2026?

GPT-4.1 significantly outperforms across most benchmarks.

Verdict: GPT-4.1 vs Kimi K2 Base — which is better?

GPT-4.1 (by OpenAI) and Kimi K2 Base (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-4.1 outperforms in 2 benchmarks (GPQA, MMLU), while Kimi K2 Base is better at 0 benchmarks. GPT-4.1 significantly outperforms across most benchmarks.

Choose GPT-4.1 if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks

Choose Kimi K2 Base if…

  • you want the most recent training data — it shipped Jul 2025
  • you need open weights you can self-host or fine-tune
Want to compare interactively?Try the playground

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

GPT-4.1 outperforms in 2 benchmarks (GPQA, MMLU), while Kimi K2 Base is better at 0 benchmarks.

GPT-4.1 significantly outperforms across most benchmarks.

Sat Jun 13 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only GPT-4.1 specifies input context (1,047,576 tokens). Only GPT-4.1 specifies output context (32,768 tokens).

OpenAI
GPT-4.1
Input1,047,576 tokens
Output32,768 tokens
Moonshot AI
Kimi K2 Base
Input- tokens
Output- tokens
Sat Jun 13 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-4.1 supports multimodal inputs, whereas Kimi K2 Base does not.

GPT-4.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-4.1

Text
Images
Audio
Video

Kimi K2 Base

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-4.1 is licensed under a proprietary license, while Kimi K2 Base uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-4.1

Proprietary

Closed source

Kimi K2 Base

MIT

Open weights

Release Timeline

When each model was launched

GPT-4.1 was released on 2025-04-14, while Kimi K2 Base was released on 2025-07-11.

Kimi K2 Base is 3 months newer than GPT-4.1.

GPT-4.1

Apr 14, 2025

1.2 years ago

Kimi K2 Base

Jul 11, 2025

11 months ago

2mo newer

Knowledge Cutoff

When training data ends

GPT-4.1 has a documented knowledge cutoff of 2024-06-01, while Kimi K2 Base's cutoff date is not specified.

We can confirm GPT-4.1's training data extends to 2024-06-01, but cannot make a direct comparison without Kimi K2 Base's cutoff date.

GPT-4.1

Jun 2024

Kimi K2 Base

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Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (1,047,576 tokens)
Supports multimodal inputs
Higher GPQA score (66.3% vs 48.1%)
Higher MMLU score (90.2% vs 87.8%)
Moonshot AI
Has open weights
OpenAIGPT-4.1
Moonshot AIKimi K2 Base
Compare in Playground

Detailed Comparison

AI Model Comparison Table
Feature
OpenAI
GPT-4.1
Moonshot AI
Kimi K2 Base

FAQ

Common questions about GPT-4.1 vs Kimi K2 Base.

Which is better, GPT-4.1 or Kimi K2 Base?

GPT-4.1 significantly outperforms across most benchmarks. GPT-4.1 is made by OpenAI and Kimi K2 Base is made by Moonshot AI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does GPT-4.1 compare to Kimi K2 Base in benchmarks?

GPT-4.1 scores MMLU: 90.2%, CharXiv-D: 87.9%, IFEval: 87.4%, MMMLU: 87.3%, MMMU: 74.8%. Kimi K2 Base scores C-Eval: 92.5%, GSM8k: 92.1%, MMLU-redux-2.0: 90.2%, MMLU: 87.8%, TriviaQA: 85.1%.

What are the context window sizes for GPT-4.1 and Kimi K2 Base?

GPT-4.1 supports 1.0M tokens and Kimi K2 Base 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 GPT-4.1 and Kimi K2 Base?

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

Who makes GPT-4.1 and Kimi K2 Base?

GPT-4.1 is developed by OpenAI and Kimi K2 Base is developed by Moonshot AI.

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