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Kimi-k1.5 vs Muse Spark Open

Muse Spark Open leads the LLM Stats Score 44.9 to 16.9.

Moonshot AI · Meta · Updated for 2026

Which is better?

Muse Spark Open leads the overall LLM Stats Score 44.9 to 16.9, ranking #43 overall.

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 Muse Spark Open

  • overall performance matters — it scores 44.9 and ranks #43 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Oct 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Kimi-k1.5
Moonshot AI
Muse Spark Open
Meta
Core performance indexes
LLM Stats Score
16.9
#242
44.9
#43
Reasoning
16.1
#239
45.2
#39
Cost, coverage & limits
Benchmark wins
—
—
Input price
— / M
$1.25 / M
Output price
— / M
$4.25 / M
Context window
—
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Kimi-k1.5
Muse Spark Open
Math
20.2#171
31.6#69
Vision
10.9#130
31.2#34
Multimodal
14.6#111
33.1#20
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for Kimi-k1.5 · 17 for Muse Spark Open

No common benchmarks found

Kimi-k1.5 and Muse Spark Opendon'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

Only Muse Spark Open specifies input context (1,048,576 tokens). Only Muse Spark Open specifies output context (1,048,576 tokens).

Moonshot AI
Kimi-k1.5
Input- tokens
Output- tokens
Meta
Muse Spark Open
Input1,048,576 tokens
Output1,048,576 tokens
Mon Oct 19 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Kimi-k1.5 and Muse Spark Open support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Kimi-k1.5

Text
Images
Audio
Video

Muse Spark Open

Text
Images
Audio
Video

License

Usage and distribution terms

Kimi-k1.5 is licensed under a proprietary license, while Muse Spark Open uses Muse Model License.

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

Kimi-k1.5

Proprietary

Closed source

Muse Spark Open

Muse Model License

Open weights

Release Timeline

When each model was launched

Kimi-k1.5 was released on 2025-01-20, while Muse Spark Open was released on 2026-10-15.

Muse Spark Open is 21 months newer than Kimi-k1.5.

Kimi-k1.5

Jan 20, 2025

1.7 years ago

Muse Spark Open

Oct 15, 2026

4 days ago

1.7yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

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

Kimi-k1.5
✓ Preferred
Muse Spark Open
Open in Playground

FAQ

Common questions about Kimi-k1.5 vs Muse Spark Open.

Which is better, Kimi-k1.5 or Muse Spark Open?

Muse Spark Open leads the LLM Stats Score 44.9 to 16.9. Kimi-k1.5 is made by Moonshot AI and Muse Spark Open is made by Meta. 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 Muse Spark Open in benchmarks?

Kimi-k1.5 scores MATH-500: 96.2%, CLUEWSC: 91.4%, C-Eval: 88.3%, MMLU: 87.4%, IFEval: 87.2%. Muse Spark Open scores MCP Atlas: 89.2%, GPQA: 89.0%, OSWorld-Verified: 80.4%, BabyVision: 80.2%, Terminal-Bench 2.1: 76.4%.

What are the context window sizes for Kimi-k1.5 and Muse Spark Open?

Kimi-k1.5 supports an unknown number of tokens and Muse Spark Open supports 1.0M 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 Muse Spark Open?

Key differences include LLM Stats Score (16.9 vs 44.9), licensing (Proprietary vs Muse Model License). See the full comparison above for benchmark-by-benchmark results.

Who makes Kimi-k1.5 and Muse Spark Open?

Kimi-k1.5 is developed by Moonshot AI and Muse Spark Open is developed by Meta.

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