Since exploding onto the scene nearly four years ago, ChatGPT has become to AI what Kleenex is to tissues: a brand so synonymous with a product that it’s often used as shorthand for an entire industry. However in all the thinkpieces, analyses, and tweets (Xs?) written about the OpenAI signature, ChatGPT’s competitors can sometimes be written off too hastily. This piece takes a look at top AI apps outside of the obvious kingpin, analyzing the LLMs rapidly advancing in acquisition, daily engagement, and deep usage — and what they’re doing to stand out. 

Timeframe & Region: U.S. user behavior from January to July 2025, based on app usage, downloads, and engagement metrics.

Side note: Understanding how consumers are engaging with LLMs like ChatGPT is now pivotal to a successful digital strategy. Early data is available for Sensor Tower's AI Chatbot Insights — learn more here. Okay, now back to the insights.

User Acquisition: Grok’s Explosive Growth 

Grok is Elon Musk’s brainchild, born out of his desire to create a truly “unfiltered” AI chatbot. In another world, Musk would be working alongside the likes of Sam Altman; but he left OpenAI’s board in 2018 following creative differences, and went on to preview Grok to select audiences in November of 2023. 

Since debuting on app stores in early 2025, Grok has experienced explosive growth. While its late entry means a smaller historical footprint, its velocity is hard to ignore. In just six months, Grok gained 8.1 million users (a 2,600% increase), making it the fastest-growing AI app in our dataset during that period, outside of ChatGPT. Downloads hit a peak in March of this year, when its voice mode was unveiled. 

Among leading LLMs, Grok is uniquely positioned to succeed at acquisition given its integration with X (formerly Twitter). Although the standalone Grok app must be installed to qualify as a download, X Premium users are able to access the chatbot within the social media platform itself, providing a built-in audience base — or at least a more frictionless journey to conversion. 

In terms of the main demographics fueling this growth, Grok is by far the most male-dominant of any of the leading AI apps — with 82.5% of its user base being male (as opposed to ChatGPT’s 68%). 

The top personas interacting with Grok are also in line with what one would expect from a Musk-driven app: Crypto Traders, Gamblers, and Peer-to-Peer Payers abound. It’s clear that, intentionally or not, Musk is cultivating a specific type of audience — and the chatbot’s ability to sustain this impressive growth into the future may or may not depend on his ability (or willingness) to draw in a more diverse crowd. 

Still, its association with X gives Grok a massive competitive advantage: Grok users are nearly 5 (4.88) times more likely to be exposed to ads on X compared to the general population, reaffirming the strong ties between the platforms — and providing myriad opportunities for fostering brand awareness and loyalty.

Daily Engagement: Gemini Cultivates a Loyal Base

Google’s Gemini relies on device integration and baked-in utility as a strategy; and so far, it seems to be working. Excluding ChatGPT, Gemini has had the largest growth in daily active users (DAUs) in the period studied — increasing their count by nearly 1.4 million from January to July of this year. That’s a 246% increase when compared to the six months prior. Crucial to this success is the fact that Android users now have the option to choose Gemini as their default assistant, with the AI soon replacing Google Assistant altogether. 

Anytime a user says the hotword “Hi Google”, Gemini is summoned. From summarizing a webpage to translating text, this ease of access captures a huge volume of hands free interactions — and is a core driver of Gemini’s notable surge in DAUs over the past six months. 

Users also have the ability to interact with Gemini in the course of using other Google products. Within Google Workspace Apps, Gemini may assist people in writing emails, analyzing data, or even taking meeting notes. While these interactions don’t directly contribute to DAUs on the Gemini app itself, the saturation of Google’s AI into everyday workflows causes both familiarity and dependence that can funnel users towards a download. 

As of mid-July, the average Gemini user accesses the app for around 12.5 minutes per week, over the course of 6.5 sessions. This would suggest that people are accessing Gemini nearly every day, but spending only a couple minutes per session. While audiences are not yet devoting large chunks of their days interacting with the AI (compare Gemini’s time spent to ChatGPT’s average of 69 mins/week), the frequency of use suggests that they are relying on it for regular, recurring tasks — a reflection that users are becoming at least somewhat reliant on the tool. Furthermore, that number is going up; weekly time spent has increased 92% year-to-date. The increase for ChatGPT over the same period was only 67%. 

If Gemini can continue its upwards trajectory through offering users both utility and ease of access, other competitors may have to reevaluate their strategies in order to keep up. 

Deep Usage: DeepSeek Racks Up Time Spent 

Chinese LLM DeepSeek has had its fair share of controversy in the time it’s been on the market. Back in early 2025, reports first surfaced that the advanced AI was alleged to have obtained Nvidia GPUs (specifically H100 chips) that were under export controls, and not permitted for sale to Chinese companies. Nvidia disputes this. Despite numerous data privacy concerns — and a bipartisan House panel labeling the company a “profound” national security threat — DeepSeek has continued to see widespread usage within the United States and outside of it. 

In the period studied, DeepSeek saw the highest growth in U.S. time spent out of any leading LLM — ChatGPT included. Average daily time spent increased by 126% from January to July, going from 6.8 to 15.5 minutes per day, spread across nearly 6 sessions. DeepSeek is differentiated from the other contenders on this list in part by the fact that it is not integrated with any other established platform, making the numbers all the more impressive. There is no X or Google equivalent bolstering its accessibility; it must stand largely on its own merit. And the platform isn’t succeeding because of shiny packaging — DeepSeek’s model is highly respected in tech communities, and in some areas rivals even ChatGPT’s level of sophistication. 

DeepSeek users are served the lion’s share of ads on Instagram (27% of impressions), YouTube (19%), and TikTok (15%),  a logical pairing given that nearly two thirds of its audience base is under 35 years old. While the controversies surrounding DeepSeek have not come to a final resolution, a lack of regulation in the space continues to serve the LLM well, as users continue to flock to both the app and webpage, engaging with the chatbot on a more consistent and lengthier basis. 

Ultimately, the battle for dominance among leading AI apps is fought on multiple levels. Some models are winning at acquisition, while others lean more into daily use or deeper interactions. For now, ChatGPT remains on top, dwarfing the competition by most available metrics. However, the contenders picking up the pace each have their unique advantages. As we keep our finger on the pulse of generative AI, stay tuned for more updates — and insights to help you leverage these trends in the most impactful way possible. 

The data in this piece comes straight from Sensor Tower's Mobile App Insights and Audience Insights products. Click below if you'd like to schedule a demo and try them out for yourself.