GPT-5 is OpenAI's fifth-generation large language model family, launched in mid-2025. The GPT-5 line introduced substantially longer context windows (up to one million tokens by the 5.4 release), improved multi-step reasoning, native tool use, and the agentic capabilities that made autonomous coworker products commercially viable.
The specific variant GPT-5.4, released on April 15, 2026, became the first frontier model to exceed the human baseline on OSWorld-V, scoring 75 percent against the 72.4 percent human professional baseline for real-world multi-application knowledge work. That milestone triggered OpenAI's April 2026 pivot toward enterprise customers and the broader repositioning of the AI industry from "copilot" to "autonomous coworker."
For deeper analysis of the GPT-5.4 capability milestone, see the CrashBytes coverage of the OSWorld-V 75 percent threshold.