List of Y Combinator Companies in California

Coinbase is a digital asset exchange company. It operates exchanges of Bitcoin, Bitcoin Cash, Ethereum, and Litecoin.

OpenSea is an online marketplace for buying and selling cryptocollectibles. The company is located in New York City and was founded in 2017.

Momentus is a Y Combinator Summer 2018 batch company developing in-space rockets powered by water plasma engines.

Airbnb is a company that provides an online platform for listing, searching, and booking rental accommodations.

​Nucypher​ is an online currency platform founded by MacLane Wilkison and Michael Egorov in 2015 and headquartered in San Francisco, California. The company offers a decentralized proxy re-encryption service.

Instacart is an internet-based grocery delivery service company.

TriNet Zenefits is a software as a service (SaaS) company providing a digital human resources platform for small- and medium-sized enterprises (SMEs).

Reddit is an online platform for social news. It allows communities to submit links, create content, and discuss any topic of their interest.

Twitch is a livestreaming video platform and community for gamers.

Stripe is a financial technology company providing software that allows businesses and individuals to make and receive online payments.

Dropbox is a file sharing and productivity startup created by Drew Houston and Arash Ferdowsi in 2007.

Pachama is a company estimating carbon storage in forests and predicting future deforestation or potential for forest restoration with the use of satellite images.

Faire is a curated boutique wholesale marketplace connecting local retailers with thousands of emerging and established brands.

Gusto is a company providing a cloud-based payroll, benefits, and human resources management platform.

Flexport is a licensed freight forwarder and shipping company based in San Francisco, CA, USA. They manage global logistics for businesses.

A microventure capital firm and syndicate in California that focuses on seed and early stage investments.

Brex is a credit card company that issues corporate credit cards with no security deposit.

GitStart is a "Pull Request as a Service" platform founded in 2019 by Hamza Zia.

Rigetti Computing is a quantum computing company based in Berkeley, California.

Vidyard is a company providing a video marketing platform for businesses. It participated in the S11 cohort of Y Combinator.

DoorDash is a San Francisco-based online food ordering and delivery platform. It participated in the S13 cohort of Y Combinator.

Mighty Buildings is a company working in the construction industry with 3D printing technology and advanced composite materials, funded by Y Combinator.

mello is a Toronto-based software company developing tools to help companies measure, track, and take action on teams wellbeing.

Zapier is an American for-profit corporation and a web-based service that allows end users to integrate the web applications they use.

Nurx is a telemedicine service company that delivers oral contraceptives and various testing kits to its customers. It was founded in 2015 and has headquarters in San Francisco, California.