Claude Surges to #1 as Pentagon Dispute Triggers Mass ChatGPT Exodus

Key Takeaways

• Claude secured the #1 position on Apple’s U.S. App Store following the Pentagon’s designation of Anthropic as a supply-chain security concern
• Pentagon chief Pete Hegseth initiated efforts to prevent defense contractors from utilizing Anthropic’s AI technology
• OpenAI announced a Pentagon partnership just hours after Anthropic’s blacklisting, fueling a #CancelChatGPT protest wave
• Anthropic reported more than 60% growth in free users since January, with daily registrations tripling from November levels
• Claude achieved top rankings in U.S., Canadian, and German App Stores, while Google Play has yet to reflect this shift

On Saturday, February 28, 2026, Anthropic’s Claude application claimed the #1 spot on Apple’s U.S. App Store for the first time in its history. The achievement displaced OpenAI’s ChatGPT to second place, while Google’s Gemini fell to fourth.

This milestone followed a high-profile confrontation between Anthropic and the United States Department of Defense. Defense Secretary Pete Hegseth pushed for Anthropic to receive a national security supply-chain risk designation. Such a classification would prevent U.S. defense contractors from accessing any of Anthropic’s AI technologies.

The controversy erupted when Anthropic declined to permit its AI systems to be utilized for widespread domestic surveillance operations or fully autonomous weapon systems. The company announced its intention to legally contest the national security designation.

President Trump entered the debate on Friday through Truth Social, declaring that Anthropic had committed a “disastrous mistake” by attempting to enforce its terms of service above what he characterized as constitutional principles.

Dario Amodei, Anthropic’s CEO, issued a response expressing the company’s desire for the Pentagon to reassess its position, emphasizing the significant value Anthropic’s technology delivers to military operations.

Mere hours following Anthropic’s blacklisting, OpenAI revealed a newly finalized agreement with the Department of Defense for model deployment. Sam Altman, OpenAI’s CEO, explained the arrangement includes safeguards against domestic mass surveillance and mandates human supervision for use-of-force decisions.

The sequence of events sparked significant blowback against OpenAI. Social media platforms saw the #CancelChatGPT hashtag gain momentum, while activists launched CancelChatGPT.com to guide users through account deletion.

Music icon Katy Perry shared an image of Claude’s Pro subscription offering on X, highlighting the $20 monthly tier with a red heart emoji. Numerous other users publicly documented their Anthropic subscription purchases alongside proof of ChatGPT account cancellations.

Anthropic’s User Expansion

Anthropic disclosed that its free user base expanded by more than 60% since the start of January. Daily new user registrations have increased threefold compared to November figures, with the company setting new sign-up records throughout that week. The paying subscriber count more than doubled during 2026.

Prior to February, Claude held the #131 position in the U.S. App Store as of January 30. Throughout most of February, it climbed into the top 20 before ultimately reaching the summit.

Claude also secured top chart positions in Canada and Germany. Switzerland saw Claude rank second, while Austria maintained ChatGPT in first place. Android users on Google Play have not yet demonstrated this trend in download patterns.

The Switch Isn’t Universal

User responses proved mixed. Various Reddit commenters indicated the Pentagon developments had no impact on their AI model preferences. Some highlighted that Anthropic maintains its own defense-related partnerships.

Anthropic established a partnership with Palantir and Amazon Web Services in November 2024. This arrangement provides U.S. intelligence and defense organizations with Claude model access, presenting similar concerns to those leveled at OpenAI.

OpenAI released complete Pentagon contract details on Saturday. The terms explicitly forbid the AI from autonomously operating weapons systems in situations where human supervision is legally mandated. The agreement also prohibits unrestricted surveillance of private data belonging to American citizens.

Anthropic launched in 2021, founded by ex-OpenAI team members. ChatGPT maintains more than 900 million weekly active users.

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