Back to Models
openai logo
openai/gpt-oss-20b%3Afree
Not Available

gpt-oss-20b (free)

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 lower-latency inference and deployability on consumer or single-GPU hardware. The model is trained in OpenAI’s Harmony response format and supports reasoning level configuration, fine-tuning, and agentic capabilities including function calling, tool use, and structured outputs.

8/5/2025
131,072 tokens
Specifications

Modalities

Input
text
Output
text

Supported Parameters

include_reasoning
max_tokens
reasoning
seed
stop
temperature
tool_choice
tools

Max Output Tokens

131,072