As both established and emerging companies race to leverage AI, a number of AI startups report that their revenue is not just increasing but also accelerating rapidly, achieving milestones in shorter time frames.

The startups listed below have exhibited a trend of such flywheel growth. It’s important to note that the metrics these companies reference vary, even when they mention “ARR.” Some may define it as annualized recurring revenue (ARR) or contracted revenue from a paying client that has yet to be billed. Others may refer to annualized run-rate revenue, which estimates annual earnings by extrapolating from the revenue of the most recent month over 12 months. Additionally, some refer to “committed ARR,” which includes contracts signed by customers who are yet to be onboarded. In Gusto’s case, it reported its actual trailing revenue for the last 12 months.

Nonetheless, each of these startups, presented in reverse order based on when their ARR growth became known, indicates that their revenue growth is picking up speed, however that may be defined. There are certainly many more rapidly growing AI startups than those mentioned here, but we are focusing this list on companies achieving revenue milestones at increasingly swift rates.

Mercor: On Monday, co-founder and CEO Brendan Foody announced that the company has surpassed $2 billion in gross annualized revenue as of June — a mere four months after reaching the $1 billion benchmark. The firm, which employs domain specialists to develop and enhance AI models, stated that it attained a $500 million run rate in September.

Anthropic: This model maker has recently seen its revenue grow at such an unprecedented pace that it has captivated the entire AI industry. In late May, Anthropic revealed that it exceeded a $47 billion revenue run rate, a noteworthy achievement that came less than two months after announcing its revenue run rate had surpassed $30 billion. The company stated it reached a $9 billion revenue run rate by late 2025, up from a previously reported $4 billion in July 2025.

Sierra: After achieving its first $100 million in ARR within seven quarters, Sierra — which creates AI agents for enterprise customer service — announced in late May that it took just two additional quarters to add another $100 million, according to co-founder and CEO Bret Taylor.

Glean: In May, Glean declared that it surpassed $300 million in ARR. While it required the seven-year-old enterprise AI startup nine months to increase its ARR from $100 million to $200 million, the company claims it only took six months to boost that figure from $200 million to $300 million.

Gusto: The 14-year-old HR tech firm revealed in May that its revenue has accelerated every quarter for the past five. Valued at $9.3 billion in early 2022, the company also disclosed that it has exceeded $1 billion in trailing 12-month revenue. Gusto’s revenue growth demonstrates that AI-native companies aren’t the only ones experiencing significant top-line growth through the use of this technology.

Clio: This 18-year-old provider of legal practice management software saw a dramatic increase in revenue after integrating AI into its services in 2023. The company reached $200 million in ARR by mid-2024, doubled that amount by the end of last year, and recently announced that its ARR has hit $500 million.