OpenAI's API business saw a growth of $1 billion in annual recurring revenue last month.

By the end of 2025, OpenAI's annual revenue had exceeded $20 billion, compared to $6 billion in 2024 and $2 billion in 2023, showing significant growth. ARR refers to the annualized value of recurring revenue from active subscriptions and contracts, usually excluding one-time payments. The API business growth announced by OpenAI on the X platform has added approximately $1 billion to single-month ARR, accounting for about 5% of the company's total ARR. It is important to note that this data reflects the additional growth portion, not the proportion of API business in total revenue. Currently, it is still unclear how much of OpenAI's total ARR comes from API clients.