LLM Perks

gpt-oss-20b

OpenAI · All GPT models
Free right now Mid-size
ReasoningTool useOpen weights

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.

ProviderContextLimitCard
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!"}]
  }'

Example for Groq. Any OpenAI-compatible client works: Cursor, Cline, OpenCode, Open WebUI.

Benchmarks

Intelligence Index
10.0
GPQA Diamond
61.1%
Humanity's Last Exam
5.3%
Terminal-Bench Hard
4.5%
τ²-Bench
50.3%
Long context (LCR)
31.0%

Source: Artificial Analysis · gpt-oss-20b (Low)

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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.