OpenAI Open Sourced GPT 2025

 OpenAI Open Sourced GPT 2025 

OpenAI Accelerates AI Accessibility with Open-Weight Models and Launches Proprietary GPT-5

San Francisco, CA – August 2025 – In a significant move for the artificial intelligence community, OpenAI has released two new open-weight models, gpt-oss-120b and gpt-oss-20b.¹ This development, which occurred in early August 2025, marks a notable step towards broader access to powerful AI tools.² However, this release is distinct from an open-sourcing of their flagship proprietary models.

Concurrently, OpenAI has also launched its next-generation proprietary model, GPT-5.³ This new iteration of the Generative Pre-trained Transformer series remains a closed-source product, available to users through OpenAI's API and various subscription tiers.

The Rise of Open-Weight Models: gpt-oss-120b and gpt-oss-20b

In a departure from their recent strategy of keeping their cutting-edge models proprietary, OpenAI has made the weights of two powerful new models publicly available.⁴ The "open-weight" designation means that while the full source code and training datasets are not released, researchers and developers can freely use and build upon the pre-trained models.⁵

• gpt-oss-120b: A 120-billion parameter model designed for a wide range of natural language processing tasks, offering performance comparable to earlier proprietary models.⁶

• gpt-oss-20b: A smaller, 20-billion parameter model optimized for efficiency and deployment in environments with limited computational resources.⁷

This initiative is seen as a move to foster innovation and allow the broader AI community to contribute to the development and safety of advanced AI systems.⁸ It also addresses the growing demand for more transparent and accessible AI technologies.

GPT-5: The New Frontier of Proprietary AI

While the open-weight models are a significant contribution to the open-source ecosystem, OpenAI continues to push the boundaries of AI with its proprietary models. The launch of GPT-5 introduces a new level of performance in areas such as reasoning, creativity, and problem-solving.⁹

Access to GPT-5 is available through a tiered system:

• Free Tier: Limited access to the new model.¹⁰

• Plus and Pro Tiers: Increased usage limits and access to more advanced features.¹¹

• Enterprise and Education: Tailored plans for organizational use.¹²

The release of GPT-5 underscores OpenAI's commitment to developing state-of-the-art AI for a variety of applications, from creative content generation to complex data analysis.¹³

Open-Source vs. Open-Weight: A Key Distinction

It is crucial to understand the difference between "open-source" and "open-weight." A fully open-source model would include the model's architecture, source code, training data, and weights.¹⁴ OpenAI's release of gpt-oss-120b and gpt-oss-20b as open-weight models provides the pre-trained model weights, which is a significant component, but not the entire training infrastructure.¹⁵

In summary, while OpenAI has not open-sourced its flagship GPT series in 2025, its release of the powerful gpt-oss open-weight models represents a major step towards empowering the global AI community. The parallel launch of the proprietary GPT-5 continues to advance the capabilities of state-of-the-art artificial intelligence.¹⁶