openai Open weights Reasoning Free tier

gpt-oss-20b (free) pricing & benchmarks

Released Aug 5, 2025 · served by 1 provider

Input / 1M tokensFree
Output / 1M tokensFree
Context window131K
Cached input
Intelligence index14.9
Coding index20.7
Agentic index3.1
1M in + 300K out$0.00

What gpt-oss-20b (free) is

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...

Providers and prices for gpt-oss-20b (free)

The same model costs different amounts depending on who serves it. Prices are per 1M tokens, cheapest first. Uptime and throughput are OpenRouter's rolling measurements, not vendor claims.

ProviderInputOutputContext QuantUptime 24hThroughput
Darkbloomcheapest Free Free 131K 97.5%

gpt-oss-20b (free) benchmark results

Design Arena head-to-head results, as reported through the OpenRouter model API.

CategoryArenaRankEloWin rate
dataviz models #100 963 39.7%
website models #115 877 27.9%

FAQ

How much does the gpt-oss-20b (free) API cost?

Free per 1M input tokens and Free per 1M output tokens.

Is gpt-oss-20b (free) free?

Yes — it is served at $0 for both input and output tokens on OpenRouter, subject to rate limits.

Which provider is cheapest for gpt-oss-20b (free)?

Darkbloom at Free input / Free output per 1M tokens.

Can I self-host gpt-oss-20b (free)?

Yes — weights are published as openai/gpt-oss-20b on Hugging Face, so you can run it on your own hardware.