Head-to-head
Claude Fable 5.1 vs Claude Sonnet 5.5
As of October 25, 2026, Claude Fable 5.1 leads Claude Sonnet 5.5 on the Analyzer Index, 93.7 to 86.7.
Normalized scores are min-maxed per benchmark across all models we track (0–100). Open the interactive compare view to add benchmarks to the radar chart or pull in more models.
Claude Fable 5.1
AnthropicClaude Sonnet 5.5
Anthropic| At a glance | Claude Fable 5.1 | Claude Sonnet 5.5 |
|---|---|---|
| Analyzer Index | 93.7 (6/13) | 86.7 (5/13) |
| Blended price | $20.00/M | $4.00/M |
| Cheapest host | maker's API | maker's API |
| Context | 1.0M | 1.0M |
| Output speed | — | 101 tok/s |
| Time to first token | — | 1.06 s |
| Benchmark | Claude Fable 5.1 | Claude Sonnet 5.5 |
|---|---|---|
Chatbot Arena Elo Arena | ||
Output Speed Speed | — | |
Time to First Token TTFT | — | |
SimpleQA Verified SimpleQA | ||
OTIS Mock AIME 2024-2025 OTIS AIME | ||
Humanity's Last Exam HLE | ||
ARC-AGI 2 ARC-AGI 2 | — | |
Frontier Composite Frontier | ||
Output Stability Stability | ||
Format Adherence Format | ||
Recovery Rate Recovery | ||
API Success Rate API OK | — | |
Safety Handling Safety |
Methodology matches the main AI Model Analyzer About page.