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.

While Elon Musk's $300 “Heavy” model puts up record-breaking benchmark scores, the basic Grok 4 struggles to keep up with competitors.