Model Comparison

Kimi-k1.5 vs o3-miniWhich is better in 2026?

o3-mini shows notably better performance in the majority of benchmarks.

Verdict: Kimi-k1.5 vs o3-mini — which is better?

Kimi-k1.5 (by Moonshot AI) and o3-mini (by OpenAI) 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.

Kimi-k1.5 outperforms in 1 benchmarks (MMLU), while o3-mini is better at 2 benchmarks (AIME 2024, IFEval). o3-mini shows notably better performance in the majority of benchmarks.

Choose Kimi-k1.5 if…

  • you are already invested in the Moonshot AI ecosystem

Choose o3-mini if…

  • you want the strongest raw capability — it leads on 2 of 3 shared benchmarks
  • you want the most recent training data — it shipped Jan 2025

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Kimi-k1.5 outperforms in 1 benchmarks (MMLU), while o3-mini is better at 2 benchmarks (AIME 2024, IFEval).

o3-mini shows notably better performance in the majority of benchmarks.

Wed Jul 29 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only o3-mini specifies input context (200,000 tokens). Only o3-mini specifies output context (100,000 tokens).

Moonshot AI
Kimi-k1.5
Input- tokens
Output- tokens
OpenAI
o3-mini
Input200,000 tokens
Output100,000 tokens
Wed Jul 29 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Kimi-k1.5 supports multimodal inputs, whereas o3-mini does not.

Kimi-k1.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Kimi-k1.5

Text
Images
Audio
Video

o3-mini

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.

Kimi-k1.5

Proprietary

Closed source

o3-mini

Proprietary

Closed source

Release Timeline

When each model was launched

Kimi-k1.5 was released on 2025-01-20, while o3-mini was released on 2025-01-30.

o3-mini is 0 month newer than Kimi-k1.5.

Kimi-k1.5

Jan 20, 2025

1.5 years ago

o3-mini

Jan 30, 2025

1.5 years ago

1w newer

Knowledge Cutoff

When training data ends

o3-mini has a documented knowledge cutoff of 2023-09-30, while Kimi-k1.5's cutoff date is not specified.

We can confirm o3-mini's training data extends to 2023-09-30, but cannot make a direct comparison without Kimi-k1.5's cutoff date.

Kimi-k1.5

o3-mini

Sep 2023

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Key Takeaways

Supports multimodal inputs
Higher MMLU score (87.4% vs 86.9%)
Larger context window (200,000 tokens)
Higher AIME 2024 score (87.3% vs 77.5%)
Higher IFEval score (93.9% vs 87.2%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Kimi-k1.5 and o3-mini side-by-side, then vote on the output you prefer.

Kimi-k1.5
✓ Preferred
o3-mini
Open in Playground
AI Model Comparison Table
Feature
Moonshot AI
Kimi-k1.5
OpenAI
o3-mini

FAQ

Common questions about Kimi-k1.5 vs o3-mini.

Which is better, Kimi-k1.5 or o3-mini?

o3-mini shows notably better performance in the majority of benchmarks. Kimi-k1.5 is made by Moonshot AI and o3-mini is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Kimi-k1.5 compare to o3-mini in benchmarks?

Kimi-k1.5 scores MATH-500: 96.2%, CLUEWSC: 91.4%, C-Eval: 88.3%, MMLU: 87.4%, IFEval: 87.2%. o3-mini scores COLLIE: 98.7%, MATH: 97.9%, IFEval: 93.9%, MGSM: 92.0%, AIME 2024: 87.3%.

What are the context window sizes for Kimi-k1.5 and o3-mini?

Kimi-k1.5 supports an unknown number of tokens and o3-mini 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 Kimi-k1.5 and o3-mini?

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

Who makes Kimi-k1.5 and o3-mini?

Kimi-k1.5 is developed by Moonshot AI and o3-mini is developed by OpenAI.