# Claude Opus 5 vs GPT-5.5 Instant

As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in 5 of 5 shared categories: General LLM, Reasoning, Science, Long context, and Factuality.

Claude Opus 5: $10 per 1M blended tokens.

GPT-5.5 Instant: price per 1M tokens is unset in the catalog.

Claude Opus 5: closed weights.

GPT-5.5 Instant: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in General LLM at #11 against #36.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in Reasoning at #9 against #38.
- Which to pick, Science: As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in Science at #12 against #65.
- Which to pick, Long context: As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in Long context at #9 against #46.
- Which to pick, Factuality: As of Oct 15, 2026, Claude Opus 5 leads GPT-5.5 Instant in Factuality at #4 against #78.

As of Oct 15, 2026, Claude Opus 5 is near state of the art, rank #4 in Factuality (since Oct 15, 2026; sources LMArena Text factuality; methodology v1.0).

As of Oct 15, 2026, GPT-5.5 Instant is ranked #36 in General LLM (since Oct 15, 2026; sources LMArena Text (style-controlled, overall); methodology v1.0).