# Claude Opus 4.5 20251101 vs Claude Opus 5.5

As of Oct 15, 2026, Claude Opus 4.5 20251101 leads Claude Opus 5.5 in 0 of 2 shared categories.

Claude Opus 4.5 20251101: price per 1M tokens is unset in the catalog.

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

Claude Opus 4.5 20251101: closed weights.

Claude Opus 5.5: closed weights.

- Which to pick, Science: As of Oct 15, 2026, Claude Opus 5.5 leads Claude Opus 4.5 20251101 in Science at #31 against #55.
- Which to pick, Abstraction (ARC): As of Oct 15, 2026, Claude Opus 5.5 leads Claude Opus 4.5 20251101 in Abstraction (ARC) at #1 against #27.

As of Oct 15, 2026, Claude Opus 4.5 20251101 is ranked #27 in Abstraction (ARC) (since Oct 15, 2026; sources ARC-AGI; methodology v1.0).

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).