OpenAI has opened up access to ChatGPT Pro to some developers for $42 a month. So far, the official cost of a subscription to the popular chatbot has not been disclosed.

On Jan. 12 OpenAI opened applications for access to the paid version of ChatGPT. The company explained that it is “thinking about monetizing ChatGPT as a way to ensure the viability of the tool in the long term.

The subscription was called ChatGPT Professional. The developers promised that the paid version of the chatbot will always be available for use (now many users of the free version see the message: ChatGPT is at capacity right now) and will generate at least twice as many responses per day compared to the free version. It will also have an early display of new features.

ChatGPT has had more than a million users since the beginning of December, and in January that number increased tenfold. OpenAI spends a lot of IT resources and money to keep the chatbot free.

Users who accessed the paid version of the chatbot said that ChatGPT Pro is much faster, but the $42 a month subscription fee is high for some countries, as not all users can afford that option.

The developers created ChatGPT on the Microsoft Azure AI supercomputer, based on OpenAI’s GPT-3.5 language model. The goal was to make the chatbot easy to use, correct and “human”. It was trained using a large number of texts from the Internet and the Reinforcement Learning from Human Feedback system.