GPT-5.3-Codex System Card

OpenAI Blog · 5 months ago

GPT-5.3-Codex combines the coding abilities of GPT-5.2-Codex with the reasoning and professional knowledge from GPT-5.2 into a single model. The system card does not specify performance benchmarks, release date, or concrete capability metrics. This combination of coding and reasoning capabilities enables more complex software development tasks previously requiring multiple models.