Is GLM 4.5 or GLM-5.1 cheaper?

GLM 4.5 is cheaper on output tokens ($2.46 vs $4.10 per 1M).

Which has the larger context window, GLM 4.5 or GLM-5.1?

GLM-5.1 has the larger context window (205K tokens).

GLM 4.5 vs GLM-5.1

GLM 4.5 is cheaper on output tokens, while GLM-5.1 offers a larger context window. Choose GLM 4.5 or GLM-5.1 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GLM 4.5	GLM-5.1
Provider	Cortecs	Cortecs
Input / 1M tokens	$0.67	$1.31
Output / 1M tokens	$2.46	$4.10
Context window	131K	205K
Parameters	355B	754B
Open weights	Yes	Yes
Released	Jul 2025	Apr 2026

GLM 4.5 details →GLM-5.1 details →

FAQ

Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.