Artificial intelligence powerhouse OpenAI has seen its weekly active users jump 33 per cent to 400 million since December, the company said on Thursday.

The San Francisco-based creator of ChatGPT also reported that its enterprise customer base has doubled to two million paying users since September, highlighting rapid adoption of AI tools across the business sector.

The company, which rocked the tech world with its release of its chatbot in 2022, however did not update the latest data for its Plus and Pro offerings, which charge customers $20 and $200 respectively.

"People hear about it through word of mouth. They see the utility of it. They see their friends using it," chief operating officer Brad Lightcap said in an interview with CNBC.

The figures come as OpenAI faces new competition from Chinese rival DeepSeek and legal challenges from OpenAI co-founder Elon Musk, who recently sued the company over its move to convert to a for-profit entity.

The proliferation of models and chatbots has sown doubt that the companies will be able to book a return on the massive investments needed to train the models.

Musk also released his AI company's latest ChatGPT rival Grok 3 on Monday.

OpenAI is currently in talks with SoftBank for a potential $40 billion investment that could value the Microsoft-backed company at approximately $300 billion, according to CNBC.

The company dismissed a recent $97.4 billion bid from Musk and other investors to purchase its nonprofit assets, with OpenAI Chairman Bret Taylor stating that the company "is not for sale."