The new coding model is the first time the brand has found its own models can be instrumental in its own development.<\/b>
\nChatGPT’s latest model, built for developers and coders, was \u201cinstrumental in creating itself\u00a0\u00bb, according to OpenAI. The latest update, ChatGPT 5.3 Codex, is aimed at developers who want tools to write and develop code faster than ever.
The blog post from OpenAI says, \u201cThe Codex team used early versions to debug its own training, manage its own deployment, and diagnose test results and evaluations \u2014 our team was blown away by how much Codex was able to accelerate its own development.\u201d
ChatGPT wasn\u2019t the primary development tool for this latest model, but GPT 5.3 Codex suggested refinements and improvements throughout the process. OpenAI says it helped to accelerate research, analyze interaction quality, and propose fixes for issues.
OpenAI says 5.3 Codex began working on improvements to itself, starting from its \u00ab\u00a0early versions.\u00a0\u00bb The company also says many researchers and engineers now say their jobs have \u00ab\u00a0fundamentally\u00a0\u00bb changed in the last couple of months because of these changes.
In an interview with Ars Technica in December, OpenAI’s product lead for Codex, Alexander Embiricos, alluded to improvements in the model’s feedback loop. He said, \u201cI think the vast majority of Codex is built by Codex, so it\u2019s almost entirely just being used to improve itself.\u00a0\u00bb
OpenAI now says its new Codex 5.3 runs 25% faster than previous versions while using fewer resources. You can now access the model through paid ChatGPT plans, with API access coming soon.
OpenAI\u2019s CEO, Sam Altman, has been clear in the past that it aims to develop AI-powered researchers to help it improve its own models. For example, he said in October last year that he wanted to build an AI research intern by September 2026 and a \u201ctrue automated\u201d AI researcher by March 2028.
Disclosure: Ziff Davis, PCMag’s parent company, filed a lawsuit against OpenAI in April 2025, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.<\/p>\n