In happier times, OpenAI CEO Sam Altman and Tesla CEO Elon Musk were buddies and business partners, but their bromance notoriously turned sour a long time ago. For the past several years, the two have very publicly hated each other and taken every opportunity they can to dunk on one another’s business pursuits. This week, Altman and Musk’s animosity spilled out into public view again, as the two attempted to determine who was the biggest liar.

The whole kerfuffle was predictably kicked off by Musk, who instigated the fight by claiming that there was some sort of corporate conspiracy to keep apps like Grok from hitting #1 on the App Store. “Apple is the gateway to the Internet for half of America,” Musk posted on Tuesday. “They are making it impossible for any other AI company to succeed by relentlessly promoting OpenAI in every way possible!” Onlookers were quick to point out that there was substantial evidence to the contrary. Indeed, several community notes appended to Musk’s tweet pointed out that other AI apps—such as DeepSeek and Perplexity—had managed to climb to the top of the App Store this year, a fact that would seem to disprove Musk’s theory of an OpenAI bias.

Not long after Musk’s tweet, Altman decided to jump into the fray: “This is a remarkable claim given what I have heard alleged that Elon does to manipulate X to benefit himself and his own companies and harm his competitors and people he doesn’t like,” the AI CEO said.

“You got 3M views on your bullshit post, you liar, far more than I’ve received on many of mine, despite me having 50 times your follower count!” Musk replied, in a post whose tenor seemed to resemble that of a petulant 8th grader.

Altman shot back with a challenge: “Will you sign an affidavit that you have never directed changes to the X algorithm in a way that has hurt your competitors or helped your own companies? i will apologize if so.”

An X user jumped into the thread and asked Grok what it thought of the argument. Humorously, Grok appeared to agree with Altman: “Based on verified evidence, Sam Altman is right. Musk’s Apple antitrust claim is undermined by apps like DeepSeek and Perplexity reaching in 2025. Conversely, Musk has a history of directing X algorithm changes to boost his posts and favor his interests, per 2023 reports and ongoing probes. Hypocrisy noted.” Not long afterward, the X account for ChatGPT shared Grok’s tweet, writing: “good bot.”

Musk subsequently sought to explain why Grok would ever say such dastardly things about its creator (newsflash: it’s the news media’s fault): “The fact that Grok is allowed to say false defamatory statements about me and they don’t get blocked or deleted (which would be easy to do) speaks to the integrity of this platform,” the billionaire claimed. “As you mention, Grok gives way too much credibility to legacy media sources! This is a major problem and we’re working to fix it,” Musk said, seemingly hinting that his chatbot is due for another lobotomy. Musk later replied to ChatGPT’s post with a screenshot purporting to show Altman’s chatbot stating that Musk was more trustworthy than Altman.

Musk has been accused many times of having rigged his social media platform in favor of his own preferred content. A study published last year claimed to show evidence that conservative content was being algorithmically amplified on X. In a similar vein, Altman shared an article on Tuesday that claimed Musk had “created a special system [on X] for showing you all his tweets first.” “I hope someone will get counter-discovery on this, I and many others would love to know what’s been happening,” Altman wrote. “But OpenAI will just stay focused on making great products.”

Musk later retaliated. “Scam Altman lies as easily as he breathes,” the billionaire posted, re-sharing a post from another user that had pointed out allegations that Altman was a liar. Gizmodo reached out to Altman via OpenAI, to Musk via Tesla, and to Apple.

When it comes to who is winning the AI war, the answer is clearly: Altman. Despite recent stumbles (GPT-5 has been hailed by many as a piece of shit) and advances from competitors (the genAI space has become notably more crowded since the first days of ChatGPT), OpenAI remains one of the most powerful and well-positioned AI companies on the market. By contrast, Musk’s xAI has made a name for itself largely by promoting the kooky personality of its chatbot, Grok. xAI is growing, however. Recent reports show that the company is burning through cash as it attempts to stand up its own expanding AI infrastructure. Despite all the money and resources that both men and their companies have managed to accrue, they don’t seem to have created chatbots that can decide which man is more trustworthy.