Claude Sonnet 5.5 vs Claude Fable 5.1: Release Comparison
Comparison of the Claude Sonnet 5.5 and Claude Fable 5.1 releases: 5 and 5 models respectively, each with different intelligence, performance, and pricing characteristics. Below is a comparison of the key metrics across all 10 models.
- For intelligence, Claude Sonnet 5.5 scores highest: Claude Sonnet 5.5 (Adaptive Reasoning, Max Effort, Default Fallback) at 56, against Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 53 for Claude Fable 5.1.
- For output speed, Claude Sonnet 5.5 is fastest: Claude Sonnet 5.5 (Adaptive Reasoning, Xhigh Effort, Default Fallback) at 171 t/s, against Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 68 t/s for Claude Fable 5.1.
- For cost per task, Claude Sonnet 5.5 is cheapest: Claude Sonnet 5.5 (Adaptive Reasoning, Low Effort, Default Fallback) at $0.41, against Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) at $2.37 for Claude Fable 5.1.
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 Sonnet 5.5 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 56 | 57 | 60 | 56 | - | 58 | 61 | $7.60 | $1.5 | $2.00 | $10.00 | $0.20 | $8,977 | 193k | 142k | 411M | - | - | - | - | - | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - |   | |
| 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 | 68 | 254.41s | 254.41s | 261.77s | 722.62s | - | 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 | 61 | 103.46s | 103.46s | 111.61s | 617.08s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 52 | 52 | 56 | 52 | - | 54 | 56 | $2.74 | $1.5 | $2.00 | $10.00 | $0.20 | $2,738 | 74k | 48k | 104M | 171 | 135.07s | 135.07s | 138.00s | 329.29s | - | 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 | 12.69s | 12.69s | 21.83s | 435.08s | - | 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 | 54 | 6.13s | 6.13s | 15.46s | 322.06s | - | 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 | 54 | 4.72s | 4.72s | 14.06s | 251.68s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 47 | 47 | 52 | 49 | - | 48 | 52 | $1.08 | $1.5 | $2.00 | $10.00 | $0.20 | $1,176 | 34k | 18k | 50M | 97 | 10.97s | 10.97s | 16.12s | 187.78s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 41 | 41 | 45 | 44 | - | 42 | 47 | $0.59 | $1.5 | $2.00 | $10.00 | $0.20 | $701 | 19k | 8k | 29M | 115 | 3.79s | 3.79s | 8.16s | 108.81s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |
| Claude Sonnet 5.5 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 36 | 37 | 41 | 40 | - | 38 | 44 | $0.41 | $1.5 | $2.00 | $10.00 | $0.20 | $544 | 14k | 5k | 23M | 93 | 1.17s | 1.17s | 6.57s | 95.30s | - | 1M | Sep 2026 | - | Yes | Supports: text and image | Supports: text | Not available | - | | |