# Claude Opus 5.5 vs Claude Sonnet 5

As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in 8 of 8 shared categories: General LLM, Reasoning, Science, Coding, Coding › Agentic, Coding › Web dev, Long context, and Factuality.

Claude Opus 5.5: $8.000000000000002 per 1M blended tokens.

Claude Sonnet 5: $4.000000000000001 per 1M blended tokens.

Claude Opus 5.5: closed weights.

Claude Sonnet 5: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in General LLM at #2 against #50.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Reasoning at #1 against #40.
- Which to pick, Science: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Science at #31 against #32.
- Which to pick, Coding: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding at #1 against #19.
- Which to pick, Coding › Agentic: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding › Agentic at #1 against #19.
- Which to pick, Coding › Web dev: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Coding › Web dev at #1 against #40.
- Which to pick, Long context: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Long context at #1 against #36.
- Which to pick, Factuality: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Sonnet 5 in Factuality at #1 against #56.

As of Oct 15, 2026, Claude Opus 5.5 is tied for state of the art in Reasoning (since Oct 2, 2026; sources LMArena Text (style-controlled, hard prompts); methodology v1.0).

As of Oct 15, 2026, Claude Sonnet 5 is ranked #19 in Coding (since Oct 15, 2026; sources Terminal-Bench 4.0; methodology v1.0).