OpenAI's API Hits 15 Billion Tokens Per Minute with GPT-5.4; ChatGPT Serves 800M Weekly Users Ahead of IPO

OpenAI's API is now processing 15 billion tokens per minute, driven by GPT-5.4, which also introduces ChatGPT integrations for Excel and Google Sheets in beta — enabling users to build, analyze, and update complex financial models within spreadsheets, with new integrations from FactSet and Moody's. Earlier, GPT-5.4 Thinking (launched March 18) shipped mid-response planning for Free and Go users, allowing course-correction without burning additional API turns, and achieved 83% on the GDPval benchmark. The WSJ published an inside look at OpenAI's finances ahead of its anticipated IPO, noting over 800 million weekly users and approximately 18 billion weekly messages by July 2025, while investor sentiment reports cite capital flows shifting toward Anthropic.