Is GPT-5.1 Codex or gpt-oss-20b cheaper?

gpt-oss-20b is cheaper on output tokens ($0.14 vs $10.00 per 1M).

Which has the larger context window, GPT-5.1 Codex or gpt-oss-20b?

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

GPT-5.1 Codex vs gpt-oss-20b

gpt-oss-20b is cheaper on output tokens, while GPT-5.1 Codex offers a larger context window. Choose GPT-5.1 Codex or gpt-oss-20b based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT-5.1 Codex	gpt-oss-20b
Provider	OpenRouter	OpenRouter
Input / 1M tokens	$1.25	$0.03
Output / 1M tokens	$10.00	$0.14
Context window	400K	131K
Parameters	—	21B
Open weights	No	Yes
Released	Nov 2025	Aug 2025

GPT-5.1 Codex details →gpt-oss-20b details →

FAQ

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