How These AI Startups Are Driving Rapid Revenue Growth

As both seasoned and new businesses rush to capitalize on AI, many AI startups are reporting not only rising revenues but also a rapid acceleration in achieving their next milestones in shorter periods.

The startups listed below demonstrate this trend of rapid expansion. It’s essential to understand that the metrics they utilize differ, even though they reference “ARR.” Some may indicate annualized recurring revenue (ARR) or revenue from paid customers that has not yet been invoiced. Others might refer to annualized run-rate revenue, estimating annual income based on the latest month’s revenue over a full year. Additionally, some mention “committed ARR,” which pertains to signed contracts from customers who are yet to onboard. For example, Gusto reported its actual trailing 12-month income.

Regardless of their definitions, each of these startups—listed in reverse order of their ARR growth disclosures—indicates that revenue growth is indeed on the rise. While there are many other rapidly growing AI startups, this list highlights those that are achieving revenue milestones at an increasingly swift pace.

Mercor: Recently, Brendan Foody, the co-founder and CEO of Mercor, announced that the company has exceeded $2 billion in gross annualized revenue as of June—just four months after reaching the $1 billion threshold. The under-three-year-old company, which employs domain experts to optimize AI models, also revealed a $500 million run rate in September.

Anthropic: In recent months, this model creator has witnessed such extraordinary revenue growth that it has captivated the entire AI sector. In late May, Anthropic disclosed that it surpassed a $47 billion revenue run rate, a milestone accomplished less than two months after reporting a run rate over $30 billion. It projected a $9 billion revenue run rate for late 2025, an increase from $4 billion reported in July 2025.

Sierra: After securing its first $100 million in ARR in only seven quarters, Sierra—known for developing AI customer service agents for enterprises—announced through co-founder and CEO Bret Taylor in late May that it took just two more quarters to add another $100 million.

Glean: In May, Glean reported exceeding $300 million in ARR. Although it took the seven-year-old enterprise AI startup nine months to scale its ARR from $100 million to $200 million, the company asserts that it took merely six months to escalate that figure from $200 million to $300 million.

Gusto: The 14-year-old HR tech firm declared in May that its revenue growth accelerated for five consecutive quarters. Valued at $9.3 billion in early 2022, it also reported exceeding $1 billion in trailing 12-month revenue. Gusto’s revenue surge demonstrates that even companies not primarily focused on AI can significantly enhance their growth by leveraging this technology.

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