gpt-oss-20b

gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.

Reasoning
Speed
Context
131K
Max output
131K
Input price
—
Output price
—
Capabilities
vision
tool call
structured output
reasoning
json mode
streaming
fine tuning
batch
Details
Provider OpenAI
Creator OpenAI
Familygpt-oss
Statusactive
Input modalitiestext
Output modalitiestext
Knowledge cutoff—
Release date—
Deprecation date—
Sourceofficial
Last updated2026-03-20
Max input—
gpt-oss family
ModelContextMax outInputOutput
gpt-oss-120bRT
131K131K——
gpt-oss-20bRT
131K131K——
API
GET/v1/models/openai/gpt-oss-20b