Claude Fable 5.1 vs Muse Spark 1.3 (xhigh)

A direct, empirical evaluation of Claude Fable 5.1 (Anthropic) against Muse Spark 1.3 (xhigh) (Meta AI).

Claude Fable 5.1

Developed by Anthropic · Proprietary Frontier parameters

Full-repository software refactoring, agentic tool workflows, formal verification, and 1.5M-token needle retrieval.

Muse Spark 1.3 (xhigh)

Developed by Meta AI · Proprietary Multimodal parameters

Autonomous codebase refactoring, terminal execution, million-token long context retrieval, and agentic workflows.

Metric Claude Fable 5.1 Muse Spark 1.3 (xhigh)
SWE-bench Verified 82.8% 75.4%
MMLU-Pro 92.4% 88.4%
MATH-500 97.9% 94.8%
Context Window 1,500,000 tokens 1,000,000 tokens
Input Pricing (per 1M) $12.00 $1.25
Output Pricing (per 1M) $60.00 $5.00

Architectural & Practical Deployment Analysis

Evaluating Claude Fable 5.1 (Anthropic) alongside Muse Spark 1.3 (xhigh) (Meta AI) highlights key technical trade-offs across neural parameter scale and compute efficiency. Claude Fable 5.1 executes across Proprietary Frontier total parameters with Dynamic Recurrent MoE active per token, whereas Muse Spark 1.3 (xhigh) operates on Proprietary Multimodal parameters with Dense Reasoner active per token.

On SWE-bench Verified software engineering tasks, Claude Fable 5.1 achieves 82.8% autonomous resolution rate, compared to 75.4% for Muse Spark 1.3 (xhigh). On complex reasoning benchmarks, Claude Fable 5.1 posts 92.4% on MMLU-Pro and 97.9% on MATH-500, against 88.4% and 94.8% respectively for Muse Spark 1.3 (xhigh).

From an operational economics perspective, processing 10,000,000 mixed tokens (7M input / 3M output) costs approximately $264.00 on Claude Fable 5.1 versus $23.75 on Muse Spark 1.3 (xhigh).

Recommendation: Deploy Claude Fable 5.1 when your infrastructure prioritizes full-repository software refactoring, agentic tool workflows, formal verification, and 1.5m-token needle retrieval.. Deploy Muse Spark 1.3 (xhigh) when workload requirements favor autonomous codebase refactoring, terminal execution, million-token long context retrieval, and agentic workflows..