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

A few weeks ago, while comparing language proficiency in essays written by ChatGPT with that in essays by human authors, I had an aha! moment. I realized that I was comparing a single voice—that of the large language model,

Grok, the artificial-intelligence chatbot produced by Elon Musk-owned xAI, this week began posting antisemitic messages in response to user queries, drawing condemnation from Jewish advocacy groups.

Elon Musk’s live demo of Grok 4, the latest big-ticket model from his AI startup, began with high-intensity music, claims of a “ludicrous rate of progress,” and a lot of chatter on X about Grok’s scandal-filled week.