# GPT-5.5 vs GPT-5.6 Luna

As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in 6 of 8 shared categories: General LLM, Reasoning, Long context, Vision, Factuality, and Abstraction (ARC).

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

GPT-5.6 Luna: $0.44999999999999996 per 1M blended tokens.

GPT-5.5: closed weights.

GPT-5.6 Luna: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in General LLM at #22 against #66.
- Which to pick, Reasoning: As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in Reasoning at #26 against #69.
- Which to pick, Science: As of Oct 15, 2026, GPT-5.6 Luna leads GPT-5.5 in Science at #25 against #30.
- Which to pick, Coding › Web dev: As of Oct 15, 2026, GPT-5.6 Luna leads GPT-5.5 in Coding › Web dev at #46 against #48.
- Which to pick, Long context: As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in Long context at #26 against #80.
- Which to pick, Vision: As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in Vision at #10 against #19.
- Which to pick, Factuality: As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in Factuality at #5 against #39.
- Which to pick, Abstraction (ARC): As of Oct 15, 2026, GPT-5.5 leads GPT-5.6 Luna in Abstraction (ARC) at #7 against #19.

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).

As of Oct 15, 2026, GPT-5.6 Luna is ranked #16 in Coding (since Oct 15, 2026; sources Terminal-Bench 4.0; methodology v1.0).