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Kimi-k1.5 vs o3-mini

Kimi-k1.5 and o3-mini are closely matched at 17.2 and 21.5 on the LLM Stats Score.

Moonshot AI · OpenAI · Updated for 2026

Which is better?

Kimi-k1.5 and o3-mini are closely matched on the overall LLM Stats Score at 17.2 and 21.5.

In the 3 individual benchmarks reported for both models, o3-mini wins 2; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Kimi-k1.5

  • you are already invested in the Moonshot AI ecosystem

Choose o3-mini

  • you value its reported benchmark strengths — it wins 2 of 3 exact shared results
  • you want the most recent training data — it shipped Jan 2025

At a glance

The differences that matter most.

Core performance indexes
17.2
#224
21.5
#193
16.4
#221
20.6
#192
Cost, coverage & limits
Benchmark wins
1 of 3
2 of 3
Input price
— / M
$1.10 / M
Output price
— / M
$4.40 / M
Context window
—
200,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Kimi-k1.5
o3-mini
20.2#161
29.3#87
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for Kimi-k1.5 · 25 for o3-mini

3 shared

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.

Sun Sep 27 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

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
Sun Sep 27 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

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

1.7 years ago

o3-mini

Jan 30, 2025

1.7 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→

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

FAQ

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

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

Kimi-k1.5 and o3-mini are closely matched on the LLM Stats Score at 17.2 and 21.5. 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 capability indexes, individual benchmarks, pricing, and limits 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 LLM Stats Score (17.2 vs 21.5), 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.