The contract signed between OpenAI and the U.S. Department of Defense has triggered a massive reaction from users. ChatGPT’s leadership on the App Store was briefly shaken. After Anthropic rejected two specific clauses in the contract, the government declared the company a “supply chain risk.” On the very day that deadline expired, OpenAI stepped in and signed the deal.
AI Wars Intensify: The Rivalry Between ChatGPT, Claude, and Google Gemini
OpenAI claimed to have implemented the security measures requested by Anthropic. Despite this, users began rapidly deleting the ChatGPT app from their phones. While deletion rates surged by 295% within a few days, Claude ranked number one on the U.S. App Store for the first time on March 1st. Shortly after, ChatGPT returned to the top, with Claude moving to second and Google Gemini to third.
This crisis coincided with a period where OpenAI’s market share has been narrowing. According to an Apptopia report, ChatGPT’s daily user share in the U.S. dropped from 69.1% in January 2025 to 45.3% in January 2026. During the same period, Google Gemini’s market share rose from 14.7% to 25.1%.
Active User Numbers and Growth Rates
Alphabet announced that Gemini has reached 750 million monthly active users. Meanwhile, OpenAI revealed last month that it surpassed 900 million weekly active users and 50 million subscribers. Data from Sensor Tower also reveals that between August and November, Gemini’s monthly user count grew by 30%, while ChatGPT’s increased by only 5%.
Anthropic Fights Back with a Lawsuit
Anthropic has long focused on the enterprise market and a “responsible AI” image. Following its Super Bowl ad, which alluded to OpenAI’s advertising strategy, the Claude app entered the top 10 on the U.S. App Store for the first time on February 13th.
Anthropic is now filing a lawsuit to halt the government’s “supply chain risk” designation, and 30 industry employees have officially lent their support to the case. These recent developments have made Claude, alongside Google Gemini, a formidable alternative in the market.
In this increasingly heated competitive environment, user preferences are shaping the market’s direction. Which AI application do you use in your daily life?
