Is GPT-5.1 Instant or GLM 4.5 cheaper?

GLM 4.5 is cheaper on output tokens ($2.20 vs $10.00 per 1M).

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

Both models offer a similar context window.

GPT-5.1 Instant vs GLM 4.5

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

Spec	GPT-5.1 Instant	GLM 4.5
Provider	Vercel AI Gateway	Vercel AI Gateway
Input / 1M tokens	$1.25	$0.60
Output / 1M tokens	$10.00	$2.20
Context window	128K	128K
Parameters	—	355B
Open weights	No	Yes
Released	Nov 2025	Jul 2025

GPT-5.1 Instant 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.