This $1 Billion AI Startup Backed By OpenAI Just Hit $100M Revenue, Racing To Beat Duolingo

A new challenger has emerged in the battle for dominance in the language learning market, and it is armed with heavy-hitting backers and a rapid growth trajectory. Speak, an AI-powered language tutor backed by the OpenAI Startup Fund and Khosla Ventures, has reportedly surpassed $100 million in annualized revenue and achieved a $1 billion valuation, cementing its status as the latest "unicorn" in the generative AI space.

The San Francisco-based startup, which recently closed a $78 million Series C funding round led by Accel, is positioning itself as the direct antithesis to market leader Duolingo. While Duolingo built an empire on gamified vocabulary drills and owl-themed notifications, Speak is betting its future on a different promise: actually getting you to talk.

The "Anti-Duolingo" Approach

Speak was founded by Connor Zwick and Andrew Hsu on a simple premise: traditional apps are great for memorizing words but terrible for teaching fluency. The company argues that users can spend years on gamified platforms without ever feeling confident enough to hold a real-world conversation.

To solve this, Speak utilizes advanced generative AI to act as an always-available conversation partner. The app encourages users to speak out loud, engaging in open-ended role-play scenarios—such as ordering coffee, checking into a hotel, or debating a topic—while providing real-time, nuanced feedback on pronunciation, grammar, and tone.

This focus on "speech-first" learning has struck a chord. The startup, which initially found massive product-market fit in South Korea, has since expanded to over 40 countries. Its rapid ascent to $100 million in revenue suggests that users are willing to pay for a tool that bridges the gap between knowing vocabulary and actually speaking a language.

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Speak’s rapid technological progress is fueled by its deep ties to OpenAI. As a portfolio company of the OpenAI Startup Fund, Speak has early access to cutting-edge models. The platform leverages OpenAI’s GPT-4o and its new Realtime API to power features like "Live Roleplays," which simulate natural, low-latency human conversation.

The company’s impressive roster of investors reads like a Who's Who of Silicon Valley. In addition to OpenAI and Khosla Ventures, Speak is backed by Y Combinator and individual tech titans like LinkedIn chairman Jeff Weiner and Y Combinator co-founder Paul Graham.

Global Expansion and Enterprise Ambitions

With its new "unicorn" status and a fresh war chest of capital, Speak is aggressively expanding beyond its stronghold in East Asia. The company plans to use its Series C funding to push deeper into the U.S., Europe, and Latin American markets, as well as to launch support for new languages beyond English, including Spanish and French.

Furthermore, Speak is making a significant play for the corporate world. Its "Speak for Business" enterprise offering is already being used by over 200 companies to train employees in business English, signaling a move to capture high-value corporate contracts alongside consumer subscriptions.

As the AI education market heats up, the race is no longer just about who has the most users, but who can deliver the most tangible results. With Speak’s rapid rise, Duolingo’s long-standing reign as the undisputed king of language apps faces its most sophisticated, AI-native threat yet.