Mux, a startup that provides performance analytics for video developers and media publishers, announced today that it has raised $9 million in a funding round led by Accel.

The B2B product targets online video publishers who need to understand what happens when they stream out their video. Although Mux can work with any video format or player, such as YouTube and Vimeo, customers do not use the product for third-party sites, according to Mux cofounder and CEO Jon Dahl. “We focus on companies or developers hosting their own video platforms,” he wrote in an email to VentureBeat.

Customers, which include PBS, Funny or Die, and Livestream, integrate Mux by installing a JavaScript library next to their Web Player or an iOS/Android software development kit (SDK) into their Mobile Player. “We are currently monitoring hundreds of millions of video streams every month,” wrote Dahl.

The startup just announced the launch of a new self-service version, which starts at $49 per month. “Our competitors start at thousands of dollars per month,” wrote Dahl, who counts Conviva and Nice People At Work (NPAW) as competitors.

Mux is a graduate of Y Combinator’s Winter 2016 batch. Two of the founders, Jon Dahl and Steve Heffernan, had previously pitched another video technology startup at YC — Zencoder (Winter 2010), which was acquired by Brightcove in 2012.

Y Combinator participated in today’s round, along with other existing investors Susa Ventures and Advancit Capital. Mux has raised a total of $11.8 million to date. The new money will be used to hire more people in engineering, sales, and marketing.

Founded in 2015, the San Francisco-based startup currently has 14 employees.

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