Claude Fable 5.1 vs Claude Sonnet 5: Release Comparison
Comparison of the Claude Fable 5.1 and Claude Sonnet 5 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 Claude Sonnet 5 (Adaptive Reasoning, Max Effort) at 38 for Claude Sonnet 5.
- For output speed, Claude Sonnet 5 is fastest: Claude Sonnet 5 (Adaptive Reasoning, Max Effort) at 84 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, Claude Sonnet 5 is cheapest: Claude Sonnet 5 (Adaptive Reasoning, Low Effort) at $0.51, 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
Cost per Intelligence Index Task
Speed & Latency
Output Speed
Capability Scores
Capability Indices
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, AutomationBench-AA, AA-LCR v1.1, GDP.pdf · Higher is better
Incorporates 7 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, Humanity's Last Exam, AA-LCR v1.1, GDP.pdf, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, GDPval-AA v2, AA-Briefcase, MLCR-AA, Humanity's Last Exam, AutomationBench-AA · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, CritPt, GDPval-AA v2, AA-Briefcase, Terminal-Bench 4.0 · Higher is better
Incorporates 5 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2, AA-Briefcase, 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 | 57 | 60 | 61 | 58 | 57 | 63 | $7.63 | $7.2 | $10.00 | $50.00 | $0.25 | $13,129 | 78k | 47k | 188M | 66 | 234.98s | 234.98s | 242.56s | 755.04s | - | 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 | 58 | 85.53s | 85.53s | 94.12s | 677.63s | - | 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 | - | 55 | 60 | $3.91 | $7.2 | $10.00 | $50.00 | $0.25 | $5,242 | 38k | 19k | 62M | 51 | 10.95s | 10.95s | 20.82s | 469.10s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Fable 5.1 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 49 | 52 | 54 | 57 | - | 52 | 58 | $2.98 | $7.2 | $10.00 | $50.00 | $0.25 | $3,983 | 28k | 12k | 44M | 51 | 7.47s | 7.47s | 17.31s | 333.43s | - | 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 | 52 | 54 | - | 49 | 55 | $2.37 | $7.2 | $10.00 | $50.00 | $0.25 | $3,158 | 22k | 8k | 33M | 50 | 5.13s | 5.13s | 15.04s | 280.39s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5 (Adaptive Reasoning, Max Effort) | Anthropic | 38 | 41 | 40 | 43 | 43 | 40 | 50 | $5.09 | $1.5 | $2.00 | $10.00 | $0.20 | $6,998 | 118k | 88k | 367M | 84 | 195.83s | 195.83s | 201.79s | 877.37s | - | 1M | Jun 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |    | |
| Claude Sonnet 5 (Adaptive Reasoning, Xhigh Effort) | Anthropic | 35 | 38 | 37 | 39 | - | 36 | 46 | $2.87 | $1.5 | $2.00 | $10.00 | $0.20 | $3,255 | 65k | 44k | 135M | 62 | 22.30s | 22.30s | 30.37s | 672.64s | - | 1M | Jun 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5 (Adaptive Reasoning, High Effort) | Anthropic | 32 | 34 | 34 | 35 | - | 32 | 42 | $1.79 | $1.5 | $2.00 | $10.00 | $0.20 | $2,086 | 44k | 28k | 89M | 58 | 2.30s | 2.30s | 10.90s | 460.65s | - | 1M | Jun 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5 (Non-reasoning, High Effort) | Anthropic | 29 | - | - | - | - | - | - | - | $1.5 | $2.00 | $10.00 | $0.20 | - | - | - | - | 58 | 1.08s | 1.08s | 9.72s | - | - | 1M | Jun 2026 | - | No | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5 (Adaptive Reasoning, Medium Effort) | Anthropic | 28 | 31 | 31 | 32 | - | 29 | 38 | $1.00 | $1.5 | $2.00 | $10.00 | $0.20 | $1,218 | 27k | 15k | 51M | 57 | 1.50s | 1.50s | 10.34s | 285.97s | - | 1M | Jun 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5 (Adaptive Reasoning, Low Effort) | Anthropic | 25 | 27 | 27 | 29 | - | 26 | 34 | $0.51 | $1.5 | $2.00 | $10.00 | $0.20 | $653 | 15k | 7k | 25M | 56 | 1.21s | 1.21s | 10.17s | 161.65s | - | 1M | Jun 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |