Duolingo has reached a $1.5 billion valuation after closing a $30 million Series F funding round from CapitalG, Alphabet’s growth equity investment fund and an existing investor in the company. This brings Duolingo’s total venture funding to $138 million and makes it Pittsburgh’s first tech startup to achieve a valuation of more than $1 billion. The new capital will be used for continued investment into the R&D of its products, and to accelerate the growth and expansion of the Duolingo team.

“CapitalG has been a valuable partner to Duolingo over the past few years, and we look forward to using this investment to continue our growth and further solidify our position as the most widely used and top-grossing language-learning app worldwide,” Duolingo CEO and co-founder Luis von Ahn said, in a statement.

In addition to San Francisco’s CapitalG, other investors have been Kleiner Perkins Caufield Byers, Union Square Ventures, New Enterprise Associates, Drive Capital, Ashton Kutcher and Tim Ferriss.

With 30 million monthly active learners, Duolingo is the most downloaded education app in the world and has grown organically through word of mouth. Since its last funding round in July 2017, the company has grown revenue via its paid subscription offering, Duolingo Plus, and is now also the top-grossing education app worldwide. Duolingo Plus removes ads and provides additional features.

“Duolingo has been adding users and revenue at an impressive pace, continuing to solidify their position as the No. 1 way to learn a language globally," CapitalG General Partner Laela Sturdy said, in a statement. “The team has demonstrated that sticking to their mission of providing free education is not only good for the world, but it’s also good for business. We are thrilled to continue to support them in this next stage of growth.”

Recent developments at the company include:

  • Product innovation – Duolingo has released podcasts to help Spanish and French learners with listening comprehension; launched Duolingo Stories to help with reading comprehension; and introduced Duolingo Events to connect learners all over the world in person to practice conversation.
  • New language courses – Duolingo added new courses for major languages such as Chinese, Korean, Hindi and Arabic, as well as endangered languages such as Navajo and Hawaiian.
  • Team growth – The company has grown from 95 employees in July 2017 to 200 today, and has opened offices in New York, Seattle and Beijing.