ChatGPT is the standalone assistant most people start with. Copilot is the same class of model wrapped inside the Microsoft stack you might already pay for.
ChatGPT wins on raw flexibility and the deeper feature set. Copilot wins if you spend the day in Word, Excel, Outlook, and Teams, because it acts on real documents instead of just talking about them.
Pick ChatGPT if you want maximum capability, custom GPTs, and the freshest features.
Pick Copilot if your work lives inside Microsoft 365 and you want AI that drafts in Word, fills cells in Excel, and summarises Teams meetings without copy-paste.
Underneath, Copilot runs on OpenAI's models, but Microsoft layers grounding, security, and Office integration on top. The behaviour is similar but not identical.
Copilot Pro for individuals is in the same price range as ChatGPT Plus. The real value of Copilot only appears if you also pay for Microsoft 365.
No. Copilot is locked to the Microsoft ecosystem. For Google Workspace, look at Gemini for Workspace instead.