Claude Fable 5.1 vs GPT-5.6 Luna: Release Comparison
Comparison of the Claude Fable 5.1 and GPT-5.6 Luna releases: 5 and 6 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 11 models.
- For intelligence, Claude Fable 5.1 scores highest: Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 53, against GPT-5.6 Luna (max) at 37 for GPT-5.6 Luna.
- For output speed, GPT-5.6 Luna is fastest: GPT-5.6 Luna (max) at 148 t/s, against Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 66 t/s for Claude Fable 5.1.
- For cost per task, GPT-5.6 Luna is cheapest: GPT-5.6 Luna (low) at $0.01, against Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) at $2.37 for Claude Fable 5.1.
Releases compared
Intelligence
Artificial Analysis Intelligence Index
Intelligence Index vs. Cost per Intelligence Index Task
Cost per Task (USD, Log Scale)
Cost
Cost per Intelligence Index Task
Speed & Latency
Output Speed
Capability Scores
Capability Indexes
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2.1, AA-Briefcase v1.1, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2.1, AA-Briefcase v1.1, Terminal-Bench 4.0 · Higher is better
Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2.1, AA-Briefcase v1.1, AA-LCR v1.1 · Higher is better
Further details
Input modality | Output modality | Weights | Provider Benchmarks | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 53 | 56 | 60 | 60 | 58 | 56 | 63 | $7.63 | $7.2 | $10.00 | $50.00 | $0.25 | $13,129 | 78k | 47k | 188M | 66 | 298.45s | 298.45s | 306.04s | 742.47s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 53 | 56 | 58 | 61 | - | 57 | 62 | $5.98 | $7.2 | $10.00 | $50.00 | $0.25 | $9,063 | 61k | 34k | 121M | 62 | 172.16s | 172.16s | 180.28s | 617.87s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 51 | 54 | 56 | 58 | - | 54 | 60 | $3.91 | $7.2 | $10.00 | $50.00 | $0.25 | $5,242 | 38k | 19k | 62M | 55 | 26.22s | 26.22s | 35.24s | 425.79s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 49 | 51 | 54 | 57 | - | 51 | 58 | $2.98 | $7.2 | $10.00 | $50.00 | $0.25 | $3,983 | 28k | 12k | 44M | 56 | 9.50s | 9.50s | 18.48s | 310.86s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 47 | 49 | 51 | 53 | - | 49 | 55 | $2.37 | $7.2 | $10.00 | $50.00 | $0.25 | $3,158 | 22k | 8k | 33M | 55 | 7.61s | 7.61s | 16.75s | 248.08s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| GPT-5.6 Luna (max) |  OpenAI | 37 | 40 | 44 | 37 | 36 | 36 | 43 | $0.18 | $0.2 | $0.20 | $1.20 | $0.02 | $320 | 41k | 28k | 154M | 148 | 122.15s | 122.15s | 125.54s | 278.44s | - | 1M | Jul 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |  | |
| GPT-5.6 Luna (xhigh) | OpenAI | 35 | 37 | 41 | 35 | 33 | 34 | 41 | $0.09 | $0.2 | $0.20 | $1.20 | $0.02 | $179 | 24k | 15k | 85M | 143 | 44.25s | 44.25s | 47.74s | 161.70s | - | 1M | Jul 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |  | |
| GPT-5.6 Luna (high) | OpenAI | 32 | 34 | 37 | 33 | 30 | 32 | 38 | $0.04 | $0.2 | $0.20 | $1.20 | $0.02 | $108 | 14k | 7k | 50M | 135 | 13.03s | 13.03s | 16.73s | 100.11s | - | 1M | Jul 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| GPT-5.6 Luna (medium) | OpenAI | 25 | 27 | 28 | 28 | 24 | 26 | 32 | $0.02 | $0.2 | $0.20 | $1.20 | $0.02 | $44 | 4k | 2k | 18M | 133 | 2.31s | 2.31s | 6.08s | 34.09s | - | 1M | Jul 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| GPT-5.6 Luna (low) | OpenAI | 21 | 23 | 22 | 24 | 20 | 23 | 28 | $0.01 | $0.2 | $0.20 | $1.20 | $0.02 | $27 | 3k | 559 | 10M | 135 | 1.75s | 1.75s | 5.46s | 18.75s | - | 1M | Jul 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| GPT-5.6 Luna (Non-reasoning) | OpenAI | 16 | 16 | 15 | 17 | - | 18 | 22 | $0.01 | $0.2 | $0.20 | $1.20 | $0.02 | $23 | 2k | 0 | 5M | 141 | 0.81s | 0.81s | 4.37s | 14.39s | - | 1M | Jul 2026 | - | No | Supports: text and image | Supports: text | Not available | - | | |