ToplineGrok, the AI chatbot launched by billionaire Elon Musk, has declined in usership throughout 2026 so far across both mobile apps and website visits, according to data from Similarweb, as many of the top AI chatbots have added users.Grok's number of daily active users on mobile devices and web declined more than 10% between March and April, according to data from Similarweb. (Photo Illustration by Nikolas Kokovlis/NurPhoto via Getty Images)NurPhoto via Getty ImagesKey FactsMusk’s Grok, which is available as a standalone app and website in addition to functionality through X, faced a steep decline in usership between March and April and has fewer users across web and mobile than it did at the beginning of 2026, Similarweb data shows.In January, Grok had the second-highest number of average daily active users on mobile apps worldwide among chatbots measured by Similarweb, a distant second behind OpenAI’s ChatGPT—but by that same metric in April, Grok placed fifth, losing ground to rivals Claude, Gemini and DeepSeek, according to Similarweb data.On mobile apps, Grok’s average number of daily active users dropped from 13.9 million in March to 12.2 million in April worldwide, a 12.5% month-over-month decline, also dropping from 1.4 million to 1.1 million daily app users over the same period in the United States, a 15.6% dip.But between March and April, Similarweb data indicates many rival chatbot apps added users: Claude’s average daily active users worldwide jumped from 16 million to 23 million between March and April, a 44% spike, while Gemini leapt from 12.4 million to 14.8 million users over the same period, about a 19% jump.Grok’s usership also declined on web, with average daily website visits worldwide falling from 10.5 million in March to 9.3 million in April, an 11.6% decline, also falling from 2.3 million U.S. web visits in March to 2.1 million in April, an 11% decline.By comparison, top competitors increased their number of web users between March and April worldwide, with Anthropic’s Claude jumping from 19.8 million average daily web visits in March to 27.5 million in April, a 39% spike, and Google’s Gemini rising from 83.7 million daily web visits in March to 92.1 million in April, a 10% increase.Forbes has reached out to xAI, Musk’s company that develops Grok, for comment.Grok's daily web visits have declined between March and April.SimilarwebWhat Ai Chatbots Are Leading The Race?OpenAI’s ChatGPT is still far and away the AI chatbot leader, according to Similarweb’s data, recording vastly higher levels of usership than all competitors. In April, ChatGPT had 244.9 million average daily active users on mobile apps worldwide, more than 10 times the 23 million daily users Claude, its closest competitor, had that month. Gemini, DeepSeek and Grok placed third, fourth and fifth in terms of daily active users on mobile apps worldwide for April. ChatGPT is also the clear leader in web visits, recording an average of 183.7 million daily web visits worldwide in April, about double that of Gemini, its closest competitor on the web.ContraThough Grok’s usership numbers have declined this year so far, activity is still up year-over-year. Grok’s average daily web visits worldwide are up 42.4% year-over-year—though that is still a modest gain compared to competitors, as Gemini’s worldwide web visits are up 575% year-over-year and Claude’s web visits are up 761% year-over-year, according to Similarweb. On mobile apps, Grok’s number of worldwide daily active users is up 83.5% year-over-year as of April. But Claude recorded a staggering 1,205% year-over-year gain as of April, while Gemini’s app usership jumped 676% year-over-year, according to Similarweb.Key BackgroundIt’s unclear exactly why Grok appears to have lost users over the past several months, though some users on the Grok subreddit appear unhappy with more features—including image and video generation—apparently being placed behind a paywall. Grok offers multiple subscription tiers, including a $10 monthly payment and a $30 monthly tier that offer higher limits of how many chats, images and videos users can create with the chatbot. Grok has also been the subject of controversy and apparent internal tumult, with xAI facing an exodus of top staffers earlier this year. Fast Company reported in April more than 80 xAI staffers left in recent months, including several co-founders. A February Financial Times report said some staffers had departed because Musk made “unreasonable demands” to improve Grok’s technology as it tried to catch up with competitors. Grok has also faced scrutiny from regulators and lawmakers over reports it had generated sexually explicit images of women and children.Forbes ValuationMusk is worth $789.2 billion as of Tuesday, according to Forbes estimates, making him the wealthiest person in the world. Musk was the first person to pass a net worth of $800 billion earlier this year. He derives much of his wealth from his stakes in Tesla and SpaceX, both of which he co-founded. TangentMusk and OpenAI CEO Sam Altman, two of the most prominent figures in the AI race, are facing off in court after Musk alleged in a lawsuit OpenAI—which he co-founded with Altman and others—reneged on its promise to function as a nonprofit entity. Musk, on the witness stand last week, said he was a “fool” to invest $38 million in the company, and engaged in testy exchanges with the cross-examiner, saying, “Without me, OpenAI wouldn’t exist.”Further ReadingMusk Suggested Settling With OpenAI Just Before Trial—Then Went On Attack, New Court Filing Shows (Forbes)Key Moments In Elon Musk’s Trial Against Sam Altman: ‘I Was A Fool’ To Fund OpenAI (Forbes)