GPT-5.3-Codex: OpenAI Unveils a 25% Faster AI Model That Goes Beyond Coding

OpenAI introduced GPT-5.3-Codex on Feb. 5, a new AI model designed to significantly expand what its Codex agent can do on a computer. The company says the model is its most capable agentic coding system yet, combining advanced coding skills with stronger reasoning and professional knowledge. According to OpenAI, GPT-5.3-Codex is 25% faster than its predecessor. It’s also built to handle long, complex tasks that can involve research, tool use, and multi-step execution.“With GPT&#