Anthropic Claude Fable 5 VS OpenAI GPT-5.6 Luna
Decision Recommendation
⚖️ Editorial Verdict: In our analysis, Claude Fable 5 is the premium intelligence choice, scoring 17.6% higher on coding benchmarks. However, this accuracy premium comes with a cost overhead: GPT-5.6 Luna is 8.9x cheaper to run. If you are building high-volume, simple chatbots or processing massive amounts of text where budget is critical, GPT-5.6 Luna offers excellent cost savings. For agentic reasoning, code refactoring, or complex logical tasks, the accuracy premium of Claude Fable 5 fully justifies the cost.
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Model Specs
Claude Fable 5
Benchmarks & Scores
Coding (swe-bench-pro)Winner (+17.6%)
80.3%excellent at multi-file repositories, autonomous agents, and industrial codebases
Reasoning (gpqa-diamond)Winner (+1.8%)
94.1%graduate-level science QA
Cost & Performance
Cost (per 1M tokens)
$20.00Input: $10.00 | Output: $50.00Context Window
1M tokensModel Specs
GPT-5.6 Luna
Benchmarks & Scores
Coding (swe-bench-pro)
62.7%excellent at multi-file repositories, autonomous agents, and industrial codebases
Reasoning (gpqa-diamond)
92.3%graduate-level science QA
Cost & Performance
Cost (per 1M tokens)8.9x cheaper
$2.25Input: $1.00 | Output: $6.00Context WindowLarger
1.05M tokensFrequently Asked Questions about Claude Fable 5 vs GPT-5.6 Luna comparison
GPT-5.6 Luna is cheaper than Claude Fable 5. GPT-5.6 Luna has a blended cost of $2.25/1M tokens, which is about 8.9x cheaper than Claude Fable 5 at $20.00/1M tokens.
Claude Fable 5 is better for coding tasks on this benchmark. It scores 80.3% on swe-bench-pro (excellent at multi-file repositories, autonomous agents, and industrial codebases) compared to GPT-5.6 Luna which scores 62.7%.
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