ChatGPT (OpenAI)

ChatGPT (OpenAI) remains the fastest and most versatile AI assistant for knowledge workers. It hit 100 million users in two months—the fastest consumer app adoption in history—and now supports 200+ million weekly active users. GPT-4o and GPT-4.5 handle writing emails, analyzing spreadsheets, and coding entire applications. The $20/month Plus subscription cuts first-draft creation time by 80%, delivering results in 5% of the usual time. Enterprise adoption crossed 92% of Fortune 500 companies by 2025. This outperforms #2 GitHub Copilot, which specializes in coding alone, by addressing broader tasks like drafting and data analysis. For sheer versatility and speed, ChatGPT is unmatched.