How OpenAI scaled ChatGPT to millions of mobile subscribers with RevenueCat

Key Outcomes

• Rapid Implementation: OpenAI moved from signing a deal, to launching ChatGPT on iOS within two months, seamlessly handling millions of new users
• Effortless Global Expansion: With RevenueCat’s support, OpenAI launched ChatGPT across multiple markets, reaching the #1 spot in app stores in the U.S., UK, Germany, and more within a week
• Custom Solution for Unprecedented Scale: RevenueCat developed a custom SDK mode that minimized backend calls enabling smooth performance even during traffic surges, and built out a custom solution to support ChatGPT’s unique integration in iOS 18
• Reliable Infrastructure: From its initial releases to many subsequent feature launches, OpenAI has experienced multiple surges in traffic. Each of these was easily absorbed by RevenueCat’s existing infrastructure that processes over 2 billion API requests daily

Moving Fast with a Reliable Partner

In December 2022, OpenAI faced a challenge: how to take ChatGPT mobile quickly while managing the explosive growth they anticipated. They needed a partner who could keep pace and help them support a massive influx of users. OpenAI turned to RevenueCat—a platform many in the team had firsthand experience with, and one they knew could deliver speed, scale, and flexibility.

“We needed a partner who could match our speed and scale—RevenueCat delivered on both,” says OpenAI Head of Financial Engineering Sara Conlon.

Custom-Built for Speed and Scale

Within weeks of the initial demo, OpenAI and RevenueCat agreed on a phased plan that enabled a quick launch while customizing the solution for future needs. Together, they developed a unique SDK mode that reduced backend calls, crucial to de-risk a sudden influx of millions of users. When OpenAI required heightened security measures, RevenueCat swiftly responded, disabling unused API endpoints and enhancing fraud protections.

“When OpenAI needed a feature or adjustment, we turned it around fast—in some cases hours or days, not weeks,” says RevenueCat CTO and co-founder Miguel Carranza.

A Flawless Launch and Rapid Global Expansion

On May 18, 2023, OpenAI’s ChatGPT app hit #1 in the U.S. App Store within 24 hours. As the rollout expanded to the UK, Germany, France, and beyond, the app continued to dominate. RevenueCat’s robust infrastructure ensured uninterrupted performance, even as demand soared. An internal note from a RevenueCat engineer captured the moment: “OpenAI traffic is not yet noticeable in the macro… still within normal traffic fluctuations.”

Driving Innovation Through Flexibility and Partnership

With RevenueCat’s support, OpenAI launched new features including Google Play Billing Library 7 for Android and integrated Apple Ad Services directly into their dashboard. Additionally, via Single Sign-On, RevenueCat enabled OpenAI’s support team to rapidly provision access to their growing user base.

More recently, to support ChatGPT’s unique direct integration into Apple’s iOS 18 and Apple Intelligence feature, RevenueCat worked with OpenAI to provide users with a seamless experience by building out support for this new subscription path.

As ChatGPT grows OpenAI has confidence that RevenueCat is a partner equipped for rapid scale and adaptability.

“With RevenueCat, we never had to slow down,” says Sara Conlon. “They made it easy to keep our focus on building the best product while ensuring our mission of accessible, safe AI for everyone.”

Reliability at Scale

OpenAI’s success depended on stability, even in the face of rapid growth and market expansions. RevenueCat’s ability to manage traffic spikes, handle app store outages, and keep service uninterrupted was crucial. RevenueCat’s “Fortress” functionality ensured that even when external APIs faltered, OpenAI users stayed connected.

Ready for What’s Next

Today, ChatGPT is a top app worldwide, with millions of subscribers and a consistent spot among the highest-grossing apps. As OpenAI continues to break records, they have a partner in RevenueCat that’s ready to scale alongside them.