Cloud-based website-testing tool BrowserStack has raised $50 million in a series A round of funding led by Accel. The company also announced the opening of its new North American headquarters in San Francisco.

Founded out of Mumbai, India in 2011, BrowserStack lets developers test how their websites perform with various operating systems, devices, and browser configurations, all through a cloud-based interface.

The company has been entirely bootstrapped until now, and it claims to have been profitable since its inception seven years ago. Though this series A round represents BrowserStack’s first outside funding, notable firms — including Microsoft, Sequoia Capital, and Warburg Pincus — have reportedly been trying to invest in the company for a while. Indeed, Accel partner Ryan Sweeney told VentureBeat that his firm had been chasing BrowserStack to take some funding for “a couple of years.”

“Accel has a long history of empowering developers, with investments in global companies like Atlassian, Slack, and PagerDuty,” said Sweeney, who also now joins BrowserStack’s board of directors. “Like these other great developer-oriented software businesses, BrowserStack puts an emphasis on making developers’ lives easier through its powerful and intuitive products. The rapid growth of software development, combined with shorter software release cycles, has put an emphasis on efficient testing processes.”

So BrowserStack, it seems, is hot property in part due to its (until now) bootstrapped success, but also thanks to the number of high-profile clients it claims — including Bose, Microsoft, MIT, Twitter, Airbnb, Barclays, Gap, and Mastercard — along with some 25,000 customers. The company also entered a partnership with Microsoft last year to allow developers to test their software on the Edge browser, following a similar tie-up with Mozilla for Firefox.

With $50 million more in the bank, BrowserStack said that it intends to grow its testing infrastructure, expand its team, and raise its brand awareness globally. The funds will also help bankroll BrowserStack’s new San Francisco hub, which will go some way toward cementing the company’s position in the lucrative North American market, where more than half its clients are already based.

“Today’s funding allows BrowserStack to invest in enhancing our testing infrastructure suite and expanding our enterprise go-to-market capabilities while maintaining our extraordinary growth trajectory — especially in the North American market, where we expect to increase our presence significantly over 2018,” said company CEO and cofounder Ritesh Arora.

Competitors in the space include San Francisco-based Sauce Labs, which has raised north of $100 million in funding, including a $70 million round a year ago.

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