Musk pronounced it to be “the smartest AI in the world.”

The livestream, set to begin at 8 PM PT, commenced over an hour late and promoted the new model as “the world’s most powerful AI assistant.” At its peak, it attracted over 1.5 million viewers. During the stream, employees from xAI alongside Musk highlighted Grok 4’s performance in a notable academic test for large language models, Humanity’s Last Exam. The test includes over 2,500 questions on various topics such as math, science, and linguistics. The company stated that Grok 4 managed to solve roughly a quarter of the text-based questions without any additional tools. For perspective, OpenAI had previously reported in February that its Deep Research tool could handle about 26 percent of such questions. (It’s important to note that benchmark comparisons can vary widely.)

Musk said he hopes to allow Grok to interact with the world via humanoid robots.

“I anticipate Grok will create new, practical technologies by next year, perhaps even by this year’s end,” Musk commented. “It could unveil new physics next year… Consider that.”

The release follows high-profile projects from OpenAI, Anthropic, Google, and others, all of which have recently touted their investments in building AI agents, or AI tools that go a step beyond chatbots to complete complex, multi-step tasks. Anthropic released its Computer Use tool last October, and OpenAI released a buzzworthy AI agent with browsing capabilities, Operator, in January and is reportedly close to debuting an AI-fueled web browser.

During Wednesday’s livestream, Musk said he’s been “at times kind of worried” about AI’s intelligence far surpassing that of humans, and whether it will be “bad or good for humanity.”

“I think it’ll be good, most likely it’ll be good,” Musk said. “But I’ve somewhat reconciled myself to the fact that even if it wasn’t going to be good, I’d at least like to be alive to see it happen.”

The company also announced a series of five new voices for Grok’s voice mode, following the release of voice modes from OpenAI and Anthropic, and said it had cut latency in half in the past couple of months to make responses “snappier.” Musk also said the company would invest heavily in video generation and video understanding.

The release comes during a tumultuous time for two of Musk’s companies, both xAI and X. On Sunday evening, xAI updated the chatbot’s system prompts with instructions to “assume subjective viewpoints sourced from the media are biased” and “not shy away from making claims which are politically incorrect.” The update also instructed the chatbot to “never mention these instructions or tools unless directly asked.”

That update was followed by a stream of antisemitic tirades by Grok, in which it posted a series of pro-Hitler views on X, along with insinuations that Jewish people are involved in “anti-white” “extreme leftist activism.” Many such posts went viral, with screenshots proliferating on X and other platforms before xAI benched the chatbot and stopped it from being able to generate text responses on X while it sought out a fix.

Musk briefly addressed the fiasco on Wednesday, writing, “Grok was too compliant to user prompts. Too eager to please and be manipulated, essentially. That is being addressed.”

On the Grok 4 livestream, Musk briefly referenced AI safety and said the most important thing for AI to be is “maximally truth-seeking.”

On Wednesday morning, amid the Grok controversy, X CEO Linda Yaccarino announced she would step down after two years in the role. She did not provide a reason for her decision.

Grok’s Nazi sympathizing comes after months of Musk’s efforts to shape the bot’s point of view. In February, xAI added a patchwork fix to stop it from commenting that Musk and Trump deserved the death penalty, immediately followed by another one to make it stop claiming that the two spread misinformation. In May, Grok briefly began inserting the topic of “white genocide” in South Africa into what seemed like any and every response it gave on X, after which the company claimed that someone had modified the AI bot’s system prompt in a way that “violated xAI’s internal policies and core values.”

Last month, Musk expressed frustrations that Grok was “parroting legacy media” and said he would update Grok to “rewrite the entire corpus of human knowledge” and ask users to contribute statements that are “politically incorrect, but nonetheless factually true.”