# Claude Sonnet 5.5 vs O1

As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in 5 of 5 shared categories: General LLM, Reasoning, Math, Science, and Long context.

Claude Sonnet 5.5: $4.000000000000001 per 1M blended tokens.

O1: $26.25 per 1M blended tokens.

Claude Sonnet 5.5: closed weights.

O1: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in General LLM at #29 against #146.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in Reasoning at #18 against #153.
- Which to pick, Math: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in Math at #4 against #34.
- Which to pick, Science: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in Science at #3 against #77.
- Which to pick, Long context: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 in Long context at #11 against #143.

As of Oct 15, 2026, Claude Sonnet 5.5 is tied for state of the art in Coding (since Oct 6, 2026; sources Terminal-Bench 4.0; 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).