Is GPT-OSS-120B-CS or GPT-5.1-Codex-Max cheaper?

GPT-OSS-120B-CS is cheaper on output tokens ($0.75 vs $9.00 per 1M).

Which has the larger context window, GPT-OSS-120B-CS or GPT-5.1-Codex-Max?

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

GPT-OSS-120B-CS vs GPT-5.1-Codex-Max

GPT-OSS-120B-CS is cheaper on output tokens, while GPT-5.1-Codex-Max offers a larger context window. Choose GPT-OSS-120B-CS or GPT-5.1-Codex-Max based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT-OSS-120B-CS	GPT-5.1-Codex-Max
Provider	Poe	Poe
Input / 1M tokens	$0.35	$1.10
Output / 1M tokens	$0.75	$9.00
Context window	128K	400K
Parameters	—	—
Open weights	No	No
Released	Aug 2025	Dec 2025

GPT-OSS-120B-CS details →GPT-5.1-Codex-Max details →

FAQ

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