# OpenAI Releases 21B Open-Weight MoE Model

> The new `gpt-oss-20b` is an Apache 2.0-licensed Mixture-of-Experts model designed to run efficiently on consumer-grade hardware.

Published by The Open Weights on Aug 4, 2025. Canonical: https://theopenweights.com/news/gpt-oss-20b-irah

## Key facts

- Company: OpenAI
- Model: gpt-oss-20b
- Version: gpt-oss-20b
- Category: Reasoning
- Modalities: Text / LLM, Reasoning
- License: Apache 2.0 (Open weights, commercial use allowed)
- Parameters: 21B (mixture of experts)
- Active parameters: 3.6B
- Context window: 131K tokens
- Architecture: GptOssForCausalLM
- Precision: INT8
- Weights size: 22.7 GB
- Significance: major
- Published: 2025-08-04
- Last verified: 2026-06-17
- Hugging Face: https://huggingface.co/openai/gpt-oss-20b
- Canonical URL: https://theopenweights.com/news/gpt-oss-20b-irah

OpenAI has released `gpt-oss-20b`, a new open-weight model that brings a powerful architecture to more accessible hardware. The model is a Mixture-of-Experts (MoE) with approximately 21 billion total parameters and is available under the permissive Apache 2.0 license, encouraging broad community use and adaptation.

The most significant aspect of this release is its focus on efficiency. MoE models achieve high performance by selectively activating only a fraction of their total parameters for any given input, which can drastically lower computational requirements compared to dense models of a similar size. This design makes `gpt-oss-20b` particularly relevant for developers and researchers working with consumer-grade GPUs.

## Capabilities and Specifications

Beyond its architecture, `gpt-oss-20b` features a large 131,072-token context window, enabling it to process and reason over very long documents or complex conversations. Its primary focus on reasoning suggests it is well-suited for tasks that require logical deduction and problem-solving.

This release provides a powerful new tool for building sophisticated AI applications on more widely available hardware. Developers can access the model weights, technical details, and usage instructions on the official [Hugging Face repository](https://huggingface.co/openai/gpt-oss-20b).

## Get the model

- [Hugging Face](https://huggingface.co/openai/gpt-oss-20b)

## Sources

- [openai/gpt-oss-20b](https://huggingface.co/openai/gpt-oss-20b) — Hugging Face, Aug 4, 2025

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Source: The Open Weights (https://theopenweights.com/). Aggregated and written by Claude, curated by humans. Cite as: "OpenAI Releases 21B Open-Weight MoE Model", The Open Weights, Aug 4, 2025, https://theopenweights.com/news/gpt-oss-20b-irah