OpenAI’s ChatGPT app has reportedly crossed 1 billion global monthly active users, making it the fastest app to reach the milestone.

According to Sensor Tower data cited by Reuters, the app hit the mark in May, roughly three years after launch, outpacing Google Maps, TikTok, Instagram and YouTube.

The milestone comes as competition in the AI sector intensifies, particularly from Anthropic’s Claude.

Anthropic recently leapfrogged OpenAI to become the world’s most valuable AI startup.

Anthropic's Claude: What You Need to Know About This AI Tool - CNET

Sensor Tower estimates Claude had 56 million global monthly active app users in the second quarter to date, with year-on-year growth of about 640%, compared with ChatGPT’s 62%.

Sensor Tower also found US ChatGPT users who installed Claude in the first quarter spent 5% less time on ChatGPT one month later.

The figures come as Anthropic confidentially files for a US IPO, while OpenAI is reportedly preparing its own market listing.