Is GPT OSS 20B or Claude Sonnet 4 cheaper?

GPT OSS 20B is cheaper on output tokens ($0.20 vs $15.00 per 1M).

Which has the larger context window, GPT OSS 20B or Claude Sonnet 4?

Claude Sonnet 4 has the larger context window (200K tokens).

GPT OSS 20B vs Claude Sonnet 4

GPT OSS 20B is cheaper on output tokens, while Claude Sonnet 4 offers a larger context window. Choose GPT OSS 20B or Claude Sonnet 4 based on the trade-off between cost, context, and the benchmarks that matter for your use case.

Spec	GPT OSS 20B	Claude Sonnet 4
Provider	FastRouter	FastRouter
Input / 1M tokens	$0.05	$3.00
Output / 1M tokens	$0.20	$15.00
Context window	131K	200K
Parameters	21B	—
Open weights	Yes	No
Released	Aug 2025	May 2025

GPT OSS 20B details →Claude Sonnet 4 details →

FAQ

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