From GPT-2 to gpt-oss: Analyzing the Architectural Advances

Welcome GPT OSS, the new open-source model family from OpenAI!

First look at GPT-5

See how a group of leading developers use GPT-5 for the first time.

Introducing GPT-5.3-Codex

GPT-5. 3-Codex is a Codex-native agent that pairs frontier coding performance with general reasoning to support long-horizon, real-world technical work.

Introducing GPT-5.1 for developers

GPT-5. 1 is now available in the API, bringing faster adaptive reasoning, extended prompt caching, improved coding performance, and new apply_patch and shell tools.

Introducing GPT-5.3-Codex-Spark

Introducing GPT-5. 3-Codex-Spark—our first real-time coding model.

Introducing gpt-oss

We’re releasing gpt-oss-120b and gpt-oss-20b—two state-of-the-art open-weight language models that deliver strong real-world performance at low cost. Available under the flexible Apache 2.

How engineers at Nextdoor use Codex to build without limits

How engineers at Nextdoor use Codex with GPT-5. 5 to investigate hard-to-reproduce issues, build across platforms, and focus on product outcomes.

Introducing GPT-4.1 in the API

Introducing GPT-4. 1 in the API—a new family of models with across-the-board improvements, including major gains in coding, instruction following, and long-context understanding.

Previewing GPT-5.6 Sol: a next-generation model

OpenAI previews GPT-5. 6 Sol, a next-generation model with stronger capabilities in coding, science, and cybersecurity, paired with its most advanced safety stack.

Introducing GPT-5.5

Introducing GPT-5. 5, our smartest model yet—faster, more capable, and built for complex tasks like coding, research, and data analysis across tools.

Unlocking Agentic RL Training for GPT-OSS: A Practical Retrospective

Introducing the GPT Store