ChatGPT has experienced a remarkable surge in growth, doubling its weekly active users in under six months. According to a new report by venture capital firm Andreessen Horowitz (a16z), ChatGPT reached 400 million weekly active users in February 2025, up from 200 million in August 2024.
Initially, its popularity was fueled by curiosity, but its sustained growth has been driven by advancements in AI models and new functionalities. The introduction of GPT-4o, which enhanced multimodal capabilities, significantly increased user engagement, especially between April and May 2024. Another spike in usage followed the launch of Advanced Voice Mode in July, with further growth seen after the release of the o1 model series in September and October.
On mobile, ChatGPT has maintained consistent growth, with users increasing by 5% to 15% each month over the past year. Currently, 175 million of its 400 million weekly users access the platform via mobile devices. Despite competition from AI rivals like DeepSeek, which rapidly climbed to No. 2 globally and captured 15% of ChatGPT’s mobile user base, ChatGPT continues to dominate. Sensor Tower data indicates that while DeepSeek users show slightly higher engagement compared to Perplexity and Claude users, it still trails behind ChatGPT in overall usage.
The report also highlights various AI development tools and provides rankings of top AI apps based on user activity and revenue. ChatGPT remains the leading AI app both in terms of unique monthly visits on the web and monthly active users on mobile, as confirmed by data from Similarweb. This consistent upward trend reaffirms ChatGPT’s stronghold in the AI market, demonstrating the impact of continuous innovation and user-focused enhancements.
