# GLM 5.1 vs GPT-5.5

As of Oct 15, 2026, GLM 5.1 leads GPT-5.5 in 0 of 6 shared categories.

GLM 5.1: $1.4834999999999998 per 1M blended tokens.

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

GLM 5.1: open weights.

GPT-5.5: closed weights.

- Which to pick, General LLM: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in General LLM at #22 against #46.
- Which to pick, Reasoning: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in Reasoning at #26 against #42.
- Which to pick, Science: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in Science at #30 against #35.
- Which to pick, Coding › Web dev: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in Coding › Web dev at #48 against #50.
- Which to pick, Long context: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in Long context at #26 against #42.
- Which to pick, Factuality: As of Oct 15, 2026, GPT-5.5 leads GLM 5.1 in Factuality at #5 against #44.

As of Oct 15, 2026, GLM 5.1 is a former state-of-the-art holder in Reasoning (since May 27, 2026; sources LMArena Text (style-controlled, hard prompts); 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).