Just two months after its launch, OpenAI's viral AI language model, ChatGPT, has been estimated to reach 100 million monthly active users in January, according to a UBS report on Wednesday.

The report, citing data from analytics firm Similarweb, said an average of about 13 million unique visitors had used ChatGPT per day in January, making it the fastest-growing consumer application in history.

In contrast, it took TikTok about nine months after its global launch to reach 100 million users and Instagram 2-1/2 years, according to data from Sensor Tower.

Backed by Microsoft Corp, the creator company, OpenAI, recently launched a $20 monthly subscription called ChatGPT Plus, that would offer subscribers continued access during peak hours.

ChatGPT user continues to grow, as more users adopt the new technology to generate codes, essays, stories and song lyrics. Some CEOs have even used it to write emails or do accounting work. The AI chatbot also recently passed medical and law exams.