The archive · Developer & Business Tools · Product decision · 2024-2025
Browser Use made websites readable to AI agents, went viral, and raised a $17M seed
Two ETH Zurich students open-sourced a layer turning websites into text AI agents can act on; Manus drove downloads to 28k/day; Felicis led a $17M seed.
Browser Use
What the business is
Open-source developer tool that converts a website's buttons and elements into a text-like format so AI agents can browse, click, and fill forms like a human.
Starting capital：$17M seed led by Felicis, with Paul Graham, A Capital, and Nexus Venture Partners (March 2025).
How it started
Founded in 2024 by Magnus Müller and Gregor Žunič, two data-science master's students at ETH Zurich, out of the university's Student Project House accelerator. Müller had spent years on web-scraping tools; the pair reasoned that combining scraping with data science could prompt a browser to perform a task. A working demo took five weeks, took off, and was open-sourced.
What happened
Browser Use turns a page's buttons and elements into a text-like format agents can act on, avoiding the screenshot navigation that breaks on dynamic sites like LinkedIn. Usage spread through YC's Winter 2025 batch — more than 20 companies in it used the tool — and exploded when Chinese startup Butterfly Effect ran its viral Manus agent on it: daily downloads quintupled to 28,000. Days after OpenAI launched Operator, the founders shipped a hosted cloud product; in March 2025 Felicis led a $17M seed with Paul Graham, A Capital, and Nexus Venture Partners.
How it ended up
Still active and scaling. The seed closed in March 2025, the open-source repo had passed 25,000 GitHub stars within three months of launch, and the company was selling Browser Use Cloud alongside the free MIT-licensed library.
Background
Browser Use began as a student experiment in turning the web into something an AI can operate. Magnus Müller, who had built web-scraping tools for years, and Gregor Žunič, a fellow data-science master's student at ETH Zurich, prototyped it in five weeks through the university's Student Project House. They open-sourced the result, and the tool spread through developers faster than any go-to-market plan could have.
The bet was that AI agents would do real work in browsers and that the missing piece was an interface layer: a way to convert any website's buttons and elements into a text-and-action format agents can act on reliably, instead of screenshots that break when sites change. The YC Winter 2025 batch proved the point — more than 20 companies in the batch ran on it.
The Manus moment made it famous: the viral Chinese agent used Browser Use to browse, and daily downloads quintupled to 28,000. Days after OpenAI launched Operator, the team shipped a hosted cloud version; Felicis then led a $17M seed with Paul Graham, A Capital, and Nexus Venture Partners. As of March 2025 it was scaling as the open-source default for browser agents.
What has to be true
- Dynamic sites break screenshot-based agents; a text-and-action layer is cheaper and more reliable, so the tool solved a felt, recurring problem.
- Open-source-first gave distribution before investors arrived — Felicis explicitly cited it as what sealed the deal.
- Being inside YC W25 made the product the default inside the most concentrated buyer pool for agent tooling.
- Hosted cloud (proxy rotation, persistent sessions, parallelism) turned an MIT-licensed library into a business.
What can be applied
Open-sourcing the infrastructure layer let a five-week student demo ride a wave it didn't create; when agents went viral, it was already the default.
Aftermath
As of late March 2025, Browser Use was post-seed and hiring in San Francisco. It ran two products: the free MIT-licensed open-source library and Browser Use Cloud, a $30/month hosted tier aimed at production automation. The founders framed the company's mission as becoming the fundamental layer that lets any LLM operate a browser — tell your computer what to do, and it gets it done.
Sources
- Browser Use, the tool making it easier for AI 'agents' to navigate websites, raises $17M
- 10 startups to watch from Y Combinator's W25 Demo Day
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