Claude Fable 5.1 vs Claude Opus 4.5
As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in 7 of 7 shared categories: General LLM, Reasoning, Math, Coding › Web dev, Long context, Factuality, and Abstraction (ARC).
Claude Fable 5.1
Yes. SOTA in co-SOTA in Factuality.
Claude Opus 4.5
It used to be. Was SOTA in Reasoning.
| Category | Claude Fable 5.1 | Claude Opus 4.5 |
|---|---|---|
| General LLM | #6 · Was SOTA · General LLM Margin 4.08163265306122 LMArena leaderboard dataset · Oct 13, 2026 | #33 · #33 in General LLM Margin 22.448979591836732 LMArena leaderboard dataset · Oct 13, 2026 |
| Reasoning | #5 · Was SOTA · Reasoning Margin 4.109589041095887 LMArena leaderboard dataset · Oct 13, 2026 | #28 · Was SOTA · Reasoning Margin 19.86301369863014 LMArena leaderboard dataset · Oct 13, 2026 |
| Math | #2 · Near-SOTA · Math Margin 2.2222222222222285 Epoch AI benchmarking hub · Sep 1, 2026 | #16 · #16 in Math Margin 33.33333333333333 Epoch AI benchmarking hub · Nov 24, 2025 |
| Science | — | #68 · #68 in Science Margin — Epoch AI benchmarking hub · Nov 24, 2025 |
| Coding | #3 · Near-SOTA · Coding Margin 18.181818181818187 Terminal-Bench Harbor Hub · Oct 6, 2026 | #— · Not enough data Margin — LMArena leaderboard dataset · Oct 13, 2026 |
| Coding › Agentic | #3 · Near-SOTA · Coding › Agentic Margin 18.181818181818187 Terminal-Bench Harbor Hub · Oct 6, 2026 | — |
| Coding › Web dev | #5 · Near-SOTA · Coding › Web dev Margin 3.738317757009341 LMArena leaderboard dataset · Oct 13, 2026 | #53 · Was SOTA · Coding › Web dev Margin 48.598130841121495 LMArena leaderboard dataset · Oct 13, 2026 |
| Long context | #6 · Was SOTA · Long context Margin 4.08163265306122 LMArena leaderboard dataset · Oct 13, 2026 | #19 · Was SOTA · Long context Margin 12.925170068027214 LMArena leaderboard dataset · Oct 13, 2026 |
| Vision | #6 · #6 in Vision Margin 18.421052631578945 Epoch AI benchmarking hub · Sep 1, 2026 | — |
| Factuality | #1 · Co-SOTA · Factuality Margin 0 LMArena leaderboard dataset · Oct 13, 2026 | #36 · #36 in Factuality Margin 27.611940298507463 LMArena leaderboard dataset · Oct 13, 2026 |
| Abstraction (ARC) | #3 · #3 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Sep 1, 2026 | #49 · #49 in Abstraction (ARC) Margin — Epoch AI benchmarking hub · Nov 24, 2025 |
Claude Fable 5.1: $20 per 1M blended tokens.
Claude Opus 4.5: $10 per 1M blended tokens.
Claude Fable 5.1: closed weights.
Claude Opus 4.5: closed weights.
General LLM: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in General LLM at #6 against #33.
Reasoning: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Reasoning at #5 against #28.
Math: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Math at #2 against #16.
Coding › Web dev: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Coding › Web dev at #5 against #53.
Long context: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Long context at #6 against #19.
Factuality: As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Factuality at #1 against #36.
Abstraction (ARC): As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Abstraction (ARC) at #3 against #49.
Claude Fable 5.1 · Claude Opus 4.5
Claude Fable 5.1 or Claude Opus 4.5?
As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in 7 of 7 shared categories: General LLM, Reasoning, Math, Coding › Web dev, Long context, Factuality, and Abstraction (ARC).
Claude Fable 5.1 or Claude Opus 4.5 for General LLM?
As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in General LLM at #6 against #33.
Claude Fable 5.1 or Claude Opus 4.5 for Reasoning?
As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Reasoning at #5 against #28.
Claude Fable 5.1 or Claude Opus 4.5 for Math?
As of Oct 15, 2026, Claude Fable 5.1 leads Claude Opus 4.5 in Math at #2 against #16.