Claude Fable 5 vs GPT-5.6 Luna: Specs & Benchmark Comparison
| Characteristic | Claude Fable 5 | GPT-5.6 Luna |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | June 9, 2026 | July 9, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.1M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $10.00 | $0.20 |
| Output Price / 1M | $50.00 | $1.20 |
| Average Score | 0.6 | 0.5 |
| Benchmarks | ||
| ExploitBench | 0.8 | 0.3 |
| SWE-Bench Pro | 0.8 | 0.6 |
| FrontierCode 1.1 | 0.5 | 0.4 |
| HealthBench Professional | 0.7 | 0.6 |
| GDP.pdf | 0.3 | 0.2 |
| DeepSWE 1.1 | 0.7 | 0.7 |
| AutomationBench | 0.2 | 0.1 |
| Terminal-Bench 2.1 | 0.8 | 0.8 |
Visual Benchmark Comparison
Claude Fable 5
GPT-5.6 Luna
ExploitBench0.8 vs 0.3
0.8
0.3
SWE-Bench Pro0.8 vs 0.6
0.8
0.6
FrontierCode 1.10.5 vs 0.4
0.5
0.4
HealthBench Professional0.7 vs 0.6
0.7
0.6
GDP.pdf0.3 vs 0.2
0.3
0.2
DeepSWE 1.10.7 vs 0.7
0.7
0.7
AutomationBench0.2 vs 0.1
0.2
0.1
Terminal-Bench 2.10.8 vs 0.8
0.8
0.8
Verdict
GPT-5.6 Luna leads in 3 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude Fable 5 — 0.6, GPT-5.6 Luna — 0.5.
API Cost
GPT-5.6 Luna is 42.9x cheaper: input $0.20/1M vs $10.00/1M tokens.
Context Window
GPT-5.6 Luna supports a larger context: 1M vs 1M tokens.
Recency
GPT-5.6 Luna is newer: released 7/9/2026 vs 6/9/2026.
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Frequently Asked Questions
Which is better for coding — Claude Fable 5 or GPT-5.6 Luna?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Fable 5 or GPT-5.6 Luna?
GPT-5.6 Luna is cheaper for input: $0.20 per 1M tokens vs $10.00.
Which has a larger context window — Claude Fable 5 or GPT-5.6 Luna?
GPT-5.6 Luna supports a larger context: 1,050,000 tokens vs 1,000,000.
The Claude Fable 5 and GPT-5.6 Luna comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Fable 5 or GPT-5.6 Luna page. See also the complete list of AI model comparisons.