The AI arena is free today

Open Superagent

Claude Fable 5.1 vs Kimi K2 Base

Claude Fable 5.1 leads the LLM Stats Score 56.3 to 13.6.

Anthropic · Moonshot AI · Updated for 2026

Which is better?

Claude Fable 5.1 leads the overall LLM Stats Score 56.3 to 13.6, ranking #2 overall.

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

Choose Claude Fable 5.1

  • overall performance matters — it scores 56.3 and ranks #2 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Kimi K2 Base

  • 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 Base
Moonshot AI
Core performance indexes
LLM Stats Score
56.3
#2
13.6
#242
Reasoning
53.3
#5
12.7
#240
Coding
35.0
#29
10.6
#161
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,000,000
—

Individual benchmarks

7 reported for Claude Fable 5.1 · 13 for Kimi K2 Base

No common benchmarks found

Claude Fable 5.1 and Kimi K2 Basedon'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 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 Base
Input- tokens
Output- tokens
Wed Sep 09 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Fable 5.1 supports multimodal inputs, whereas Kimi K2 Base 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 Base

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Fable 5.1 is licensed under a proprietary license, while Kimi K2 Base 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 Base

MIT

Open weights

Release Timeline

When each model was launched

Claude Fable 5.1 was released on 2026-09-01, while Kimi K2 Base was released on 2025-07-11.

Claude Fable 5.1 is 14 months newer than Kimi K2 Base.

Claude Fable 5.1

Sep 1, 2026

1 weeks ago

1.1yr newer
Kimi K2 Base

Jul 11, 2025

1.2 years 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 Base side-by-side, then vote on the output you prefer.

Claude Fable 5.1
✓ Preferred
Kimi K2 Base
Open in Playground

FAQ

Common questions about Claude Fable 5.1 vs Kimi K2 Base.

Which is better, Claude Fable 5.1 or Kimi K2 Base?

Claude Fable 5.1 leads the LLM Stats Score 56.3 to 13.6. Claude Fable 5.1 is made by Anthropic and Kimi K2 Base 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 Base 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 Base scores C-Eval: 92.5%, GSM8k: 92.1%, MMLU-redux-2.0: 90.2%, MMLU: 87.8%, TriviaQA: 85.1%.

What are the context window sizes for Claude Fable 5.1 and Kimi K2 Base?

Claude Fable 5.1 supports 1.0M tokens and Kimi K2 Base 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 Base?

Key differences include LLM Stats Score (56.3 vs 13.6), 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 Base?

Claude Fable 5.1 is developed by Anthropic and Kimi K2 Base is developed by Moonshot AI.

Related comparisons