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

The AI chatbot Grok, which is produced by Elon Musk’s xAI, wrote numerous antisemitic social media posts Tuesday after the artificial intelligence company released a revamped version of it over the weekend. The posts ranged from alleging "patterns" about Jewish people to praising Hitler.

Stay tuned for further changes in the coming months, and please send news tips to: will.oremus@washpost.com A chatbot created by Elon Musk’s artificial intelligence company launched into an antisemitic tirade Tuesday and invoked Adolf Hitler,