# Claude Opus 5.5 vs GLM 5.1

As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in 6 of 6 shared categories: General LLM, Reasoning, Science, Coding › Web dev, Long context, and Factuality.

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

GLM 5.1: $1.4834999999999998 per 1M blended tokens.

Claude Opus 5.5: closed weights.

GLM 5.1: open weights.

- Which to pick, General LLM: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in General LLM at #2 against #46.
- Which to pick, Reasoning: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in Reasoning at #1 against #42.
- Which to pick, Science: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in Science at #31 against #35.
- Which to pick, Coding › Web dev: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in Coding › Web dev at #1 against #50.
- Which to pick, Long context: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in Long context at #1 against #42.
- Which to pick, Factuality: As of Oct 15, 2026, Claude Opus 5.5 leads GLM 5.1 in Factuality at #1 against #44.

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).

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).