OpenAI shipped GPT-5.4 on March 5, 2026, making it the first general-purpose model with built-in computer-use capabilities — reading screens and controlling mouse and keyboard without a wrapper layer. It scored 75% on OSWorld, crossing the human expert baseline of 72.4% that no prior model had reached. The release also carries a 1M-token context window, 33% fewer factual errors versus GPT-5.3, and a 47% gain in token efficiency; mini and nano variants followed on March 17.