# Claude Sonnet 4.5 20250929 vs GPT-5.5

As of Oct 15, 2026, Claude Sonnet 4.5 20250929 leads GPT-5.5 in 0 of 2 shared categories.

Claude Sonnet 4.5 20250929: price per 1M tokens is unset in the catalog.

GPT-5.5: $11.25 per 1M blended tokens.

Claude Sonnet 4.5 20250929: closed weights.

GPT-5.5: closed weights.

- Which to pick, Science: As of Oct 15, 2026, GPT-5.5 leads Claude Sonnet 4.5 20250929 in Science at #30 against #66.
- Which to pick, Abstraction (ARC): As of Oct 15, 2026, GPT-5.5 leads Claude Sonnet 4.5 20250929 in Abstraction (ARC) at #7 against #36.

As of Oct 15, 2026, Claude Sonnet 4.5 20250929 is ranked #36 in Abstraction (ARC) (since Oct 15, 2026; sources ARC-AGI; methodology v1.0).

As of Oct 15, 2026, GPT-5.5 is near state of the art, rank #5 in Factuality (since Oct 15, 2026; sources LMArena Text factuality; methodology v1.0).