# Claude Fable 5.1 vs O1

As of Oct 15, 2026, Claude Fable 5.1 leads O1 in 5 of 5 shared categories: General LLM, Reasoning, Math, Long context, and Abstraction (ARC).

Claude Fable 5.1: $20 per 1M blended tokens.

O1: $26.25 per 1M blended tokens.

Claude Fable 5.1: closed weights.

O1: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Fable 5.1 leads O1 in General LLM at #6 against #146.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Fable 5.1 leads O1 in Reasoning at #5 against #153.
- Which to pick, Math: As of Oct 15, 2026, Claude Fable 5.1 leads O1 in Math at #2 against #34.
- Which to pick, Long context: As of Oct 15, 2026, Claude Fable 5.1 leads O1 in Long context at #6 against #143.
- Which to pick, Abstraction (ARC): As of Oct 15, 2026, Claude Fable 5.1 leads O1 in Abstraction (ARC) at #3 against #57.

As of Oct 15, 2026, Claude Fable 5.1 is tied for state of the art in Factuality (since Oct 2, 2026; sources LMArena Text factuality; methodology v1.0).

As of Oct 15, 2026, O1 is a former state-of-the-art holder in General LLM (since Jan 28, 2025; sources LMArena Text (style-controlled, overall); methodology v1.0).