Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback)
Anthropic • text#15 of 616 in intelligence
Specifications
Context Window
—
Input Price/1M
$10.00
#713 of 744
Output Price/1M
$50.00
Parameters
—
Speed
47 tok/s
#300 of 602
Latency (TTFT)
6.2s
Cost per Task
2.4
AA Score / US$ · higher = better
Benchmarks
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) results on the main AI model evaluation benchmarks. Higher scores indicate better performance.
Coding
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA Coding Index | 75.2 | 100.0 | Artificial Analysis official API |
overall
| Benchmark | Score | Maximum | Methodology |
|---|---|---|---|
| AA Intelligence Index | 47.0 | 100.0 | Artificial Analysis official API |
Information
- Release date
- September 01, 2026
- Tool Calling
- ❌ Not supported
- Vision
- ❌ Not supported
- Audio
- ❌ Not supported
Full Analysis: Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback)
What is Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback)?
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) is an AI model developed by Anthropic, classified as a text model. It focuses on text processing and natural language generation. As a proprietary model, it is available via Anthropic's cloud API.
Pricing & Costs in 2026
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) is usage-based, priced at $10/1M input tokens and $50/1M output tokens. For context: 1 million tokens is approximately 750,000 words, or about 10 average-length books. The premium pricing reflects the model's frontier capabilities, recommended for complex reasoning, analysis, and generation tasks where quality takes priority over cost.
Benchmarks & Performance
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) was evaluated on 2 different benchmarks, covering categories like Coding, overall. Results show moderate performance across available evaluations.
It's important to note that benchmarks measure specific aspects and don't capture the full user experience. Factors like instruction adherence, behavior in long conversations, and real-world task quality vary significantly between models and aren't always reflected in standard scores.
Recommended Use Cases
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) specializes in text, offering advanced capabilities for creating and processing text content.
Comparison with Alternatives
In the 2026 AI model ecosystem, Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) competes directly with similarly capable models. Key competitors include GPT (OpenAI), Gemini (Google), and open source models like Llama (Meta) and DeepSeek. The choice between models depends on the specific use case, budget, latency requirements, and need for features like multimodality and tool calling.
For a detailed side-by-side comparison, use our comparison tool or check the overall model ranking.
Frequently Asked Questions
What is Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback)?
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) is an AI model developed by Anthropic. It is a text model.
How much does Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) cost?
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) costs $10/1M input tokens and $50/1M output tokens. For heavy usage (e.g., a chatbot handling 100k messages/month), costs can range from $10 to $1,000 depending on volume.
How does Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) compare with other models?
In available benchmarks, Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) scored: AA Coding Index: 75.2/100, AA Intelligence Index: 47/100. See the full table above for a detailed comparison.
Is Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) open source?
No, Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) is a proprietary model from Anthropic. It is available via cloud API. For open source alternatives, check our open source model ranking.
What is Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) best for?
Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) excels at general-purpose language tasks.
Last updated: September 12, 2026 • View methodology →