Is GPT-5.1 Codex or GLM-5.1 cheaper?

GLM-5.1 is cheaper on output tokens ($4.40 vs $8.50 per 1M).

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

GPT-5.1 Codex has the larger context window (400K tokens).

GPT-5.1 Codex vs GLM-5.1

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

Spec	GPT-5.1 Codex	GLM-5.1
Provider	OpenCode Zen	OpenCode Zen
Input / 1M tokens	$1.07	$1.40
Output / 1M tokens	$8.50	$4.40
Context window	400K	205K
Parameters	—	754B
Open weights	No	Yes
Released	Nov 2025	Apr 2026

GPT-5.1 Codex 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.