aiaimodel.cards

gpt-oss-120b

Language modelOpen weightsCard summarized

Most powerful open-weight model, fits into an H100 GPU

Overview

OpenAI · 04gpt-oss, front

gpt-oss-120b

Most powerful open-weight model, fits into an H100 GPU

Cost
$0.037 host
Context
128K
Cheapest host
$0.037 / $0.17
Max output
128K
Knows up to
June 2024
Released
5 Aug 2025

gpt-oss-120b is the larger of OpenAI's two open-weight reasoning models: a text-only Mixture-of-Experts transformer with 116.8B total and 5.1B active parameters, released under Apache 2.0. It is built for agentic workflows with tool use, Structured Outputs, adjustable reasoning effort and full chain-of-thought. OpenAI reports it beats o3-mini and approaches o4-mini on its main benchmarks, and that even adversarially fine-tuned it did not reach High capability in biology/chemistry or cyber. §1, §2

openai/gpt-oss-120b
Input / output per 1M
$0.037 / $0.17 via DeepInfra
Context window
128K
Max output
128K
Knows up to
June 2024
Reasoning
Configurable (low / medium / high)
Weights
Open · Apache 2.0 (plus gpt-oss usage policy)

About this card. A model card is the maker's own account of a model: what it's for, how it was trained and tested, and where it falls short. This page condenses OpenAI's gpt-oss-120b & gpt-oss-20b Model Card. Every claim carries its source page.