Is GPT OSS 120B or GPT-5.5 Pro cheaper?

GPT OSS 120B is cheaper on output tokens ($0.15 vs $180.00 per 1M).

Which has the larger context window, GPT OSS 120B or GPT-5.5 Pro?

GPT-5.5 Pro has the larger context window (1.1M tokens).

GPT OSS 120B vs GPT-5.5 Pro

GPT OSS 120B is cheaper on output tokens, while GPT-5.5 Pro offers a larger context window. Choose GPT OSS 120B or GPT-5.5 Pro based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT OSS 120B	GPT-5.5 Pro
Provider	OpenRouter	OpenRouter
Input / 1M tokens	$0.03	$30.00
Output / 1M tokens	$0.15	$180.00
Context window	131K	1.1M
Parameters	117B	—
Open weights	Yes	No
Released	Aug 2025	Apr 2026

GPT OSS 120B details →GPT-5.5 Pro details →

FAQ

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