OpenAI releases its most powerful programming model, GPT-5.1-Codex-Max.

OpenAI released the GPT-5.1-Codex-Max programming model, replacing GPT-5.1-Codex and becoming the default model in the Codex integration interface. The model outperformed Google Gemini 3 Pro in multiple programming benchmarks, such as achieving 77.9% accuracy in the SWE-Bench Verified test, leading by 1.7 percentage points. It incorporates a "compression" mechanism, allowing it to work continuously for over 24 hours, and improving token efficiency by approximately 30%.