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Kimi K2.8 Preview vs o3-mini

Comparing Kimi K2.8 Preview and o3-mini across benchmarks, pricing, and capabilities.

Moonshot AI · OpenAI · Updated for 2026

Which is better?

Kimi K2.8 Preview and o3-mini trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.

Kimi K2.8 Preview also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

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

Choose Kimi K2.8 Preview

  • you process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Sep 2026

Choose o3-mini

  • you want predictable pricing at $1.10/M input and $4.40/M output

At a glance

The differences that matter most.

Benchmark wins
Input price
— / M
$1.10 / M
Output price
— / M
$4.40 / M
Context window
1,048,576
200,000

Individual benchmarks

0 reported for Kimi K2.8 Preview · 25 for o3-mini

No common benchmarks found

Kimi K2.8 Preview and o3-minidon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Kimi K2.8 Preview accepts 1,048,576 input tokens compared to o3-mini's 200,000 tokens. Only o3-mini specifies output context (100,000 tokens).

Moonshot AI
Kimi K2.8 Preview
Input1,048,576 tokens
Output- tokens
OpenAI
o3-mini
Input200,000 tokens
Output100,000 tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Kimi K2.8 Preview supports multimodal inputs, whereas o3-mini does not.

Kimi K2.8 Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.

Kimi K2.8 Preview

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 K2.8 Preview

Proprietary

Closed source

o3-mini

Proprietary

Closed source

Release Timeline

When each model was launched

Kimi K2.8 Preview was released on 2026-09-11, while o3-mini was released on 2025-01-30.

Kimi K2.8 Preview is 20 months newer than o3-mini.

Kimi K2.8 Preview

Sep 11, 2026

3 days ago

1.6yr newer
o3-mini

Jan 30, 2025

1.6 years ago

Knowledge Cutoff

When training data ends

o3-mini has a documented knowledge cutoff of 2023-09-30, while Kimi K2.8 Preview'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 K2.8 Preview's cutoff date.

Kimi K2.8 Preview

o3-mini

Sep 2023

Provider Availability

Kimi K2.8 Preview is available from Moonshot AI. o3-mini is available from Azure, OpenAI.

Kimi K2.8 Preview

moonshot logo
Unknown Organization

o3-mini

azure logo
Azure
Input Price:Input: $1.10/1MOutput Price:Output: $4.40/1M
openai logo
OpenAI
Input Price:Input: $1.10/1MOutput Price:Output: $4.40/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Kimi K2.8 Preview and o3-mini side-by-side, then vote on the output you prefer.

Kimi K2.8 Preview
✓ Preferred
o3-mini
Open in Playground

FAQ

Common questions about Kimi K2.8 Preview vs o3-mini.

Which is better, Kimi K2.8 Preview or o3-mini?

Kimi K2.8 Preview (Moonshot AI) and o3-mini (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Kimi K2.8 Preview compare to o3-mini in benchmarks?

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 K2.8 Preview and o3-mini?

Kimi K2.8 Preview supports 1.0M 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 K2.8 Preview and o3-mini?

Key differences include context window (1.0M vs 200K), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Kimi K2.8 Preview and o3-mini?

Kimi K2.8 Preview is developed by Moonshot AI and o3-mini is developed by OpenAI.