Is Z.AI GLM-5.1 or GPT-5.5 cheaper?

Z.AI GLM-5.1 is cheaper on output tokens ($4.40 vs $15.00 per 1M).

Which has the larger context window, Z.AI GLM-5.1 or GPT-5.5?

GPT-5.5 has the larger context window (272K tokens).

Z.AI GLM-5.1 vs GPT-5.5

Z.AI GLM-5.1 is cheaper on output tokens, while GPT-5.5 offers a larger context window. Choose Z.AI GLM-5.1 or GPT-5.5 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	Z.AI GLM-5.1	GPT-5.5
Provider	FrogBot	FrogBot
Input / 1M tokens	$1.40	$2.50
Output / 1M tokens	$4.40	$15.00
Context window	198K	272K
Parameters	—	—
Open weights	Yes	No
Released	Jan 2025	Mar 2026

Z.AI GLM-5.1 details →GPT-5.5 details →

FAQ

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