gpt-oss-20b
gpt-oss-20b is a language model with 21B parameters from OpenAI. It is currently free at 4 providers with up to 131K tokens of context. The model supports step-by-step reasoning, supports tool calling. Its weights are open, so it can also run locally.
- Developer
- OpenAI
- Parameters
- 21B / 3.6B active
- Context
- 131K tokens
- Type
- Text
- License
- Open weights
- Free since
- September 19, 2026
Where to use gpt-oss-20b for free
Each row is a separate free endpoint with its own limits.
| Provider | Context | Limit | Card | |
|---|---|---|---|---|
Groq openai/gpt-oss-20b |
131K | 14,400 req/day | No | Open |
Cloudflare Workers AI @cf/openai/gpt-oss-20b |
128K | Workers Free: 10,000 Neurons/day shared across eligible models | — | Open |
NVIDIA Build openai/gpt-oss-20b |
— | Free serverless inference for development; limits and model availability may change. | No | Open |
UnoRouter gpt-oss-20b:free |
128K | No-card free models use shared capacity and per-model limits; availability can change. | No | Open |
Quick start
curl https://api.groq.com/openai/v1/chat/completions \
-H "Authorization: Bearer $GROQ_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "openai/gpt-oss-20b",
"messages": [{"role": "user", "content": "Hello!"}]
}'from openai import OpenAI
client = OpenAI(
base_url="https://api.groq.com/openai/v1",
api_key="YOUR_GROQ_API_KEY",
)
reply = client.chat.completions.create(
model="openai/gpt-oss-20b",
messages=[{"role": "user", "content": "Hello!"}],
)
print(reply.choices[0].message.content)import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://api.groq.com/openai/v1",
apiKey: process.env.GROQ_API_KEY,
});
const reply = await client.chat.completions.create({
model: "openai/gpt-oss-20b",
messages: [{ role: "user", content: "Hello!" }],
});
console.log(reply.choices[0].message.content);Example for Groq. Any OpenAI-compatible client works: Cursor, Cline, OpenCode, Open WebUI.
Benchmarks
Source: Artificial Analysis · gpt-oss-20b (Low)
Similar free models
FAQ
Is gpt-oss-20b free?
Yes. As of October 24, 2026, gpt-oss-20b is free at Groq, Cloudflare Workers AI, NVIDIA Build, UnoRouter. Each provider has its own limits — see the table above.
What is the context window of gpt-oss-20b?
The largest context among free routes is 131,072 tokens. Some providers cap it lower.
How do I call gpt-oss-20b via API?
Use any OpenAI-compatible client with base URL https://api.groq.com/openai/v1, model ID openai/gpt-oss-20b, and a Groq key.
How good is gpt-oss-20b?
Artificial Analysis Intelligence Index: 10.0, GPQA Diamond: 61%. For comparison, the strongest free model in the catalog right now is DeepSeek V4.1 Flash.
Is gpt-oss-20b open-weight?
Yes, the weights are published — you can download and run it locally, for example with Ollama or LM Studio.