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Atria Dawn Preview vs Claude Fable 5.1

Atria Dawn Preview and Claude Fable 5.1 are closely matched at 52.3 and 55.7 on the LLM Stats Score.

Shanghai AI Laboratory · Anthropic · Updated for 2026

Which is better?

Atria Dawn Preview and Claude Fable 5.1 are closely matched on the overall LLM Stats Score at 52.3 and 55.7.

The models split the 2 individual benchmarks reported for both models evenly.

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

Choose Atria Dawn Preview

  • you want the most recent training data — it shipped Sep 2026
  • you need open weights you can self-host or fine-tune

Choose Claude Fable 5.1

  • you want predictable pricing at $10.00/M input and $50.00/M output

At a glance

The differences that matter most.

Atria Dawn Preview
Shanghai AI Laboratory
Claude Fable 5.1
Anthropic
Core performance indexes
LLM Stats Score
52.3
#10
55.7
#2
Reasoning
50.5
#12
52.8
#5
Coding
36.2
#22
35.5
#26
Agents
38.8
#10
41.3
#2
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
— / M
$10.00 / M
Output price
— / M
$50.00 / M
Context window
—
1,000,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Atria Dawn Preview
Claude Fable 5.1
Tool use
31.1#12
30.2#18
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

12 reported for Atria Dawn Preview · 7 for Claude Fable 5.1

2 shared

Atria Dawn Preview outperforms in 1 benchmarks (AutomationBench), while Claude Fable 5.1 is better at 1 benchmark (GDPval-AA).

Both models are evenly matched across the benchmarks.

Sun Sep 20 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).

Shanghai AI Laboratory
Atria Dawn Preview
Input- tokens
Output- tokens
Anthropic
Claude Fable 5.1
Input1,000,000 tokens
Output128,000 tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Fable 5.1 supports multimodal inputs, whereas Atria Dawn Preview does not.

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

Atria Dawn Preview

Text
Images
Audio
Video

Claude Fable 5.1

Text
Images
Audio
Video

License

Usage and distribution terms

Atria Dawn Preview is licensed under MIT, while Claude Fable 5.1 uses a proprietary license.

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

Atria Dawn Preview

MIT

Open weights

Claude Fable 5.1

Proprietary

Closed source

Release Timeline

When each model was launched

Atria Dawn Preview was released on 2026-09-11, while Claude Fable 5.1 was released on 2026-09-01.

Atria Dawn Preview is 0 month newer than Claude Fable 5.1.

Atria Dawn Preview

Sep 11, 2026

1 weeks ago

1w newer
Claude Fable 5.1

Sep 1, 2026

2 weeks 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 Atria Dawn Preview and Claude Fable 5.1 side-by-side, then vote on the output you prefer.

Atria Dawn Preview
✓ Preferred
Claude Fable 5.1
Open in Playground

FAQ

Common questions about Atria Dawn Preview vs Claude Fable 5.1.

Which is better, Atria Dawn Preview or Claude Fable 5.1?

Atria Dawn Preview and Claude Fable 5.1 are closely matched on the LLM Stats Score at 52.3 and 55.7. Atria Dawn Preview is made by Shanghai AI Laboratory and Claude Fable 5.1 is made by Anthropic. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Atria Dawn Preview compare to Claude Fable 5.1 in benchmarks?

Atria Dawn Preview scores DeepSearchQA: 96.0%, BrowseComp: 92.5%, CyberGym: 86.5%, MLE-Bench Lite: 86.2%, WideSearch: 81.9%. 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%.

What are the context window sizes for Atria Dawn Preview and Claude Fable 5.1?

Atria Dawn Preview supports an unknown number of tokens and Claude Fable 5.1 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 Atria Dawn Preview and Claude Fable 5.1?

Key differences include LLM Stats Score (52.3 vs 55.7), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Atria Dawn Preview and Claude Fable 5.1?

Atria Dawn Preview is developed by Shanghai AI Laboratory and Claude Fable 5.1 is developed by Anthropic.

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