Is GLM-5.1 or GLM 4.5 cheaper?

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

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

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

GLM-5.1 vs GLM 4.5

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

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

GLM-5.1 details →GLM 4.5 details →

FAQ

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