Model Comparison

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

Kimi K2 Instruct significantly outperforms across most benchmarks. Kimi K2 Instruct is 7.0x cheaper per token.

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

GPT-4.1 (by OpenAI) and Kimi K2 Instruct (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 (Humanity's Last Exam, MMLU), while Kimi K2 Instruct is better at 7 benchmarks (Aider-Polyglot, AIME 2024, AIME 2025, GPQA, HMMT 2025, IFEval, Multi-Challenge). Kimi K2 Instruct significantly outperforms across most benchmarks.

On price, Kimi K2 Instruct is roughly 7.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-4.1 also accepts a larger context window (1,047,576 input tokens), making it the stronger choice for long documents and large codebases.

Choose GPT-4.1 if…

  • you process long inputs — it offers a 1,047,576 token context window

Choose Kimi K2 Instruct if…

  • you want the strongest raw capability — it leads on 7 of 9 shared benchmarks
  • cost matters — it's about 7.0x cheaper per token
  • you want the most recent training data — it shipped Jul 2025
  • you need open weights you can self-host or fine-tune
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Performance Benchmarks

Comparative analysis across standard metrics

9 benchmarks

GPT-4.1 outperforms in 2 benchmarks (Humanity's Last Exam, MMLU), while Kimi K2 Instruct is better at 7 benchmarks (Aider-Polyglot, AIME 2024, AIME 2025, GPQA, HMMT 2025, IFEval, Multi-Challenge).

Kimi K2 Instruct significantly outperforms across most benchmarks.

Thu Jun 25 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Kimi K2 Instruct costs less

For input processing, GPT-4.1 ($2.00/1M tokens) is 4.0x more expensive than Kimi K2 Instruct ($0.50/1M tokens).

For output processing, GPT-4.1 ($8.00/1M tokens) is 16.0x more expensive than Kimi K2 Instruct ($0.50/1M tokens).

In conclusion, GPT-4.1 is more expensive than Kimi K2 Instruct.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Thu Jun 25 2026 • llm-stats.com
OpenAI
GPT-4.1
Input tokens$2.00
Output tokens$8.00
Best providerOpenAI
Moonshot AI
Kimi K2 Instruct
Input tokens$0.50
Output tokens$0.50
Best providerFireworks
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

GPT-4.1 accepts 1,047,576 input tokens compared to Kimi K2 Instruct's 200,000 tokens. Kimi K2 Instruct can generate longer responses up to 200,000 tokens, while GPT-4.1 is limited to 32,768 tokens.

OpenAI
GPT-4.1
Input1,047,576 tokens
Output32,768 tokens
Moonshot AI
Kimi K2 Instruct
Input200,000 tokens
Output200,000 tokens
Thu Jun 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

GPT-4.1 supports multimodal inputs, whereas Kimi K2 Instruct 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 Instruct

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-4.1 is licensed under a proprietary license, while Kimi K2 Instruct 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 Instruct

MIT

Open weights

Release Timeline

When each model was launched

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

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

GPT-4.1

Apr 14, 2025

1.2 years ago

Kimi K2 Instruct

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 Instruct'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 Instruct's cutoff date.

GPT-4.1

Jun 2024

Kimi K2 Instruct

—

Provider Availability

GPT-4.1 is available from OpenAI. Kimi K2 Instruct is available from Fireworks, Novita.

GPT-4.1

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $8.00/1M

Kimi K2 Instruct

fireworks logo
Fireworks
Input Price:Input: $0.50/1MOutput Price:Output: $0.50/1M
novita logo
Novita
Input Price:Input: $0.57/1MOutput Price:Output: $2.30/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

OpenAI
Larger context window (1,047,576 tokens)
Supports multimodal inputs
Higher Humanity's Last Exam score (5.4% vs 4.7%)
Higher MMLU score (90.2% vs 89.5%)
Moonshot AI
Less expensive input tokens
Less expensive output tokens
Has open weights
Higher Aider-Polyglot score (60.0% vs 51.6%)
Higher AIME 2024 score (69.6% vs 48.1%)
Higher AIME 2025 score (49.5% vs 46.4%)
Higher GPQA score (75.1% vs 66.3%)
Higher HMMT 2025 score (38.8% vs 28.9%)
Higher IFEval score (89.8% vs 87.4%)
Higher Multi-Challenge score (54.1% vs 38.3%)
OpenAIGPT-4.1
Moonshot AIKimi K2 Instruct
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Detailed Comparison

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

FAQ

Common questions about GPT-4.1 vs Kimi K2 Instruct.

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

Kimi K2 Instruct significantly outperforms across most benchmarks. GPT-4.1 is made by OpenAI and Kimi K2 Instruct 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 Instruct in benchmarks?

GPT-4.1 scores MMLU: 90.2%, CharXiv-D: 87.9%, IFEval: 87.4%, MMMLU: 87.3%, MMMU: 74.8%. Kimi K2 Instruct scores MATH-500: 97.4%, GSM8k: 97.3%, CBNSL: 95.6%, HumanEval: 93.3%, MMLU-Redux: 92.7%.

Is GPT-4.1 cheaper than Kimi K2 Instruct?

Kimi K2 Instruct is 4.0x cheaper for input tokens. GPT-4.1 costs $2.00/M input and $8.00/M output via openai. Kimi K2 Instruct costs $0.50/M input and $0.50/M output via fireworks.

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

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

Key differences include context window (1.0M vs 200K), input pricing ($2.00 vs $0.50/M), 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 Instruct?

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

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