Claude Fable 5.1 vs Claude Opus 5: Release Comparison
Comparison of the Claude Fable 5.1 and Claude Opus 5 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 Fable 5.1 scores highest: Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 66, against Claude Opus 5 (Adaptive Reasoning, Max Effort) at 63 for Claude Opus 5.
- For output speed, Claude Fable 5.1 is fastest: Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) at 66 t/s, against Claude Opus 5 (Adaptive Reasoning, Max Effort) at 52 t/s for Claude Opus 5.
- For cost per task, Claude Opus 5 is cheapest: Claude Opus 5 (Adaptive Reasoning, Low Effort) at $0.43, against Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) at $0.77 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
Measures performance in agentic workflows, focusing on behaviors like tool use, planning, autonomy, and complex problem solving.
Incorporates 5 evaluations: AA-Omniscience, GDPval-AA v2, Humanity's Last Exam, 𝜏³-Banking, AA-LCR · Higher is better
Incorporates 4 evaluations: AA-Omniscience, GDPval-AA v2, 𝜏³-Banking, AA-LCR · Higher is better
Incorporates 5 evaluations: AA-Omniscience, GDPval-AA v2, AA-LCR, 𝜏³-Banking, Humanity's Last Exam · Higher is better
Incorporates 5 evaluations: AA-Omniscience, GDPval-AA v2, MLCR-AA, Humanity's Last Exam, 𝜏³-Banking · Higher is better
Incorporates 6 evaluations: AA-Omniscience, Humanity's Last Exam, GPQA Diamond, CritPt, GDPval-AA v2, Terminal-Bench v2.1 · Higher is better
Incorporates 4 evaluations: AA-Omniscience, Humanity's Last Exam, GDPval-AA v2, AA-LCR · Higher is better
Further details
Weights | Provider Benchmarks | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Claude Fable 5.1 (Adaptive Reasoning, Max Effort, Default Fallback) |  Anthropic | 66 | - | 1M | $7.2 | 66 | Not available | | |
| Claude Fable 5.1 (Adaptive Reasoning, Xhigh Effort, Default Fallback) | Anthropic | 65 | - | 1M | $7.2 | 59 | Not available | | |
| Claude Opus 5 (Adaptive Reasoning, Max Effort) | Anthropic | 63 | - | 1M | $3.9 | 52 | Not available |   | |
| Claude Opus 5 (Adaptive Reasoning, Xhigh Effort) | Anthropic | 63 | - | 1M | $3.9 | 51 | Not available | | |
| Claude Fable 5.1 (Adaptive Reasoning, High Effort, Default Fallback) | Anthropic | 62 | - | 1M | $7.2 | 49 | Not available | | |
| Claude Opus 5 (Adaptive Reasoning, High Effort) | Anthropic | 61 | - | 1M | $3.9 | 47 | Not available | | |
| Claude Fable 5.1 (Adaptive Reasoning, Medium Effort, Default Fallback) | Anthropic | 60 | - | 1M | $7.2 | 48 | Not available | | |
| Claude Opus 5 (Adaptive Reasoning, Medium Effort) | Anthropic | 59 | - | 1M | $3.9 | 47 | Not available | | |
| Claude Fable 5.1 (Adaptive Reasoning, Low Effort, Default Fallback) | Anthropic | 58 | - | 1M | $7.2 | 56 | Not available | | |
| Claude Opus 5 (Adaptive Reasoning, Low Effort) | Anthropic | 52 | - | 1M | $3.9 | 49 | Not available | |