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Claude Fable 5.1 vs Kimi K2-Instruct-0905

Claude Fable 5.1 leads the LLM Stats Score 56.8 to 21.7.

Anthropic · Moonshot AI · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 56.8 to 21.7, ranking #2 overall.

In the 1 individual benchmarks reported for both models, Claude Fable 5.1 wins 1; 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 Claude Fable 5.1

  • overall performance matters — it scores 56.8 and ranks #2 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Sep 2026

Choose Kimi K2-Instruct-0905

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Claude Fable 5.1
Anthropic
Kimi K2-Instruct-0905
Moonshot AI
Core performance indexes
LLM Stats Score
56.8
#2
21.7
#176
Reasoning
53.9
#5
22.0
#164
Coding
36.0
#22
10.0
#159
Agents
41.9
#2
-4.2
#169
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Fable 5.1
Kimi K2-Instruct-0905
Tool use
30.7#12
7.4#135
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

7 reported for Claude Fable 5.1 · 29 for Kimi K2-Instruct-0905

1 shared

Claude Fable 5.1 outperforms in 1 benchmarks (Humanity's Last Exam), while Kimi K2-Instruct-0905 is better at 0 benchmarks.

Claude Fable 5.1 significantly outperforms across most benchmarks.

Fri Sep 04 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Fable 5.1 specifies input context (1,000,000 tokens). Only Claude Fable 5.1 specifies output context (128,000 tokens).

Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Moonshot AI
Kimi K2-Instruct-0905
Input- tokens
Output- tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Fable 5.1 supports multimodal inputs, whereas Kimi K2-Instruct-0905 does not.

Claude Fable 5.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Fable 5.1

Text
Images
Audio
Video

Kimi K2-Instruct-0905

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Fable 5.1 is licensed under a proprietary license, while Kimi K2-Instruct-0905 uses MIT.

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

Claude Fable 5.1

Proprietary

Closed source

Kimi K2-Instruct-0905

MIT

Open weights

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while Kimi K2-Instruct-0905 was released on 2025-09-05.

Claude Fable 5.1 is 12 months newer than Kimi K2-Instruct-0905.

Claude Fable 5.1

Sep 1, 2026

2 days ago

12mo newer
Kimi K2-Instruct-0905

Sep 5, 2025

12 months ago

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?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Fable 5.1 and Kimi K2-Instruct-0905 side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
Kimi K2-Instruct-0905
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs Kimi K2-Instruct-0905.

Which is better, Claude Fable 5.1 or Kimi K2-Instruct-0905?

Claude Fable 5.1 leads the LLM Stats Score 56.8 to 21.7. Claude Fable 5.1 is made by Anthropic and Kimi K2-Instruct-0905 is made by Moonshot AI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Fable 5.1 compare to Kimi K2-Instruct-0905 in benchmarks?

Claude Fable 5.1 scores OSWorld 2.0: 77.9%, CursorBench v3.2: 73.4%, Humanity's Last Exam: 65.0%, GDPval-AA: 61.8%, Terminal-Bench 4.0: 55.8%. Kimi K2-Instruct-0905 scores MATH-500: 97.4%, MMLU-Redux: 92.7%, IFEval: 89.8%, AutoLogi: 89.5%, MMLU: 89.5%.

What are the context window sizes for Claude Fable 5.1 and Kimi K2-Instruct-0905?

Claude Fable 5.1 supports 1.0M tokens and Kimi K2-Instruct-0905 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Fable 5.1 and Kimi K2-Instruct-0905?

Key differences include LLM Stats Score (56.8 vs 21.7), multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Fable 5.1 and Kimi K2-Instruct-0905?

Claude Fable 5.1 is developed by Anthropic and Kimi K2-Instruct-0905 is developed by Moonshot AI.

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