OpenAI’s ChatGPT reached 1 billion global monthly active users in roughly three years. Sensor Tower data confirms this is the fastest adoption rate for any app in history.
The milestone surpasses previous records set by TikTok, Instagram, and Google Maps. Those platforms required between five and eight years to reach the same user count.
ChatGPT’s monthly active users grew 62% year-over-year as of May 2026.
Anthropic's rival Claude app saw its user base surge by approximately 640% year-over-year. Claude reached 56 million global monthly active users in the second quarter to date.