Built using huge amounts of computing power at a Tennessee data center, Grok is Musk's attempt to outdo rivals such as OpenAI's ChatGPT and Google's Gemini in building an AI assistant that shows its reasoning before answering a question.

Grok 4 is xAI’s most advanced model yet, but early praise is clashing with old scandals and fresh tests of its limits.

Elon Musk’s artificial intelligence startup xAI is rolling out Grok 4 just months after releasing its previous iteration, underscoring the frenetic pace of AI development.