OpenAI has recently unveiled Codex, a revolutionary coding tool aimed at software developers. Alongside this launch, OpenAI also introduced a cutting-edge model called GPT-5.3 Codex, designed to enhance the capabilities of Codex.
According to OpenAI, the integration of GPT-5.3 Codex elevates Codex from a tool that can simply “write and review code” to one that can perform a wide range of tasks typically handled by developers and professionals. The company has conducted tests comparing the performance of this new model to various benchmarks, showcasing its ability to create intricate games and applications from scratch within a matter of days.
OpenAI highlights that GPT-5.3 Codex boasts a 25 percent increase in speed compared to its predecessor, GPT-5.2. Additionally, it is the first model developed by the company that played a pivotal role in its own creation, as OpenAI’s team utilized early versions of the program to fine-tune and evaluate its performance.
The introduction of this new model comes shortly after Anthropic, a competitor of OpenAI, released its own agentic coding model. Initially scheduled for a simultaneous launch at 10 a.m. PST, Anthropic decided to move up its release time by 15 minutes, slightly edging out OpenAI in unveiling their respective models.
