GitHub announced that OpenAI's latest code generation model, GPT-5.3-Codex, has been officially rolled out in GitHub Copilot. The company stated that in multiple internal benchmark tests, the new model demonstrated significant improvements in reasoning capabilities and the execution of complex, long-duration workflows that rely on multiple tools. In practical applications, GPT-5.3-Codex has improved overall performance in 'agentic' coding tasks by approximately 25% compared to GPT-5.2-Codex, substantially reducing developer wait times.
