# Claude Sonnet 5.5 vs O1 Preview

As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 Preview in 4 of 4 shared categories: General LLM, Reasoning, Science, and Long context.

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

O1 Preview: price per 1M tokens is unset in the catalog.

Claude Sonnet 5.5: closed weights.

O1 Preview: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 Preview in General LLM at #29 against #166.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 Preview in Reasoning at #18 against #177.
- Which to pick, Science: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 Preview in Science at #3 against #125.
- Which to pick, Long context: As of Oct 15, 2026, Claude Sonnet 5.5 leads O1 Preview in Long context at #11 against #176.

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 Preview is a former state-of-the-art holder in General LLM (since Sep 27, 2024; sources LMArena Text (style-controlled, overall); methodology v1.0).