Y Combinator Open menuAboutWhat Happens at YC?ApplyYC Interview GuideFAQPeopleYC Blog CompaniesStartup DirectoryFounder DirectoryLaunch YC Library Partners ResourcesStartup SchoolNewsletterRequests for StartupsFor InvestorsVerify FoundersHacker NewsBookfaceSAFEFind a Co-FounderEvents Startup Jobs Log inApply YC turns builders into formidable founders[1] Airbnb Brian, Joe, and Nate did YC in W09. Airbnb went public in 2020 at an over $100B valuation. YC Now OpenAI Sam was part of YC's inaugural batch in S05 and founded OpenAI as YC Research in 2015. Sam built OpenAI into a $500B company. YC Now Stripe The Collison brothers did YC twice—first in W07 and then in S09, when they started Stripe. Stripe is now the internet’s $107B payments backbone. YC Now Coinbase Fred and Brian met on Reddit and did YC in S12. Coinbase went public in 2021 at a $86B valuation. YC Now DoorDash Andy, Stanley, Tony, and Evan did YC in S13. DoorDash went public in 2020 at a valuation of $39B. YC Now Scale AI Alexandr and Lucy did YC S16 and pivoted during the batch. In 2025, Meta acquired 49% of Scale for over $14B. YC Now Dropbox Arash and Drew started Dropbox at MIT and did YC in S07. Dropbox had the biggest tech IPO of 2018 at a $9B valuation. YC Now Reddit Alexis and Steve were in the inaugural YC batch in S05. Reddit went public in 2024 at a $6.4B valuation. YC Now Instacart Apoorva, Max, and Brandon did YC in S12. Instacart went public in 2023 at a $10B valuation. YC Now GitLab Sid and Dmytro did YC in S14. GitLab went public in 2021 at an $11B valuation. YC Now Kalshi Tarek and Luana did YC in W19. Kalshi reached an $11B valuation in 2025. YC Now Replit Haya and Amjad interviewing for the YC W18 batch. Replit became a leading AI coding platform valued at over $9B. YC Now Twitch Michael, Justin, Kyle, and Emmett in YC W07. Twitch was acquired by Amazon for nearly $1B. YC Now [1] “A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.” — Paul Graham YC turns builders into formidable founders[1] [1] “A formidable person is one who seems like they’ll get what they want, regardless of whatever obstacles are in the way.” — Paul Graham During YC Sam was part of YC's inaugural batch in S05 and founded OpenAI as YC Research in 2015. During YC Brian, Joe, and Nate did YC in W09. During YC The Collison brothers did YC twice—first in W07 and then in S09, when they started Stripe. During YC Fred and Brian met on Reddit and did YC in S12. During YC Andy, Stanley, Tony, and Evan did YC in S13. During YC Alexandr and Lucy did YC S16 and pivoted during the batch. During YC Arash and Drew started Dropbox at MIT and did YC in S07. During YC Alexis and Steve were in the inaugural YC batch in S05. During YC Apoorva, Max, and Brandon did YC in S12. During YC Sid and Dmytro did YC in S14. During YC Tarek and Luana did YC in W19. During YC Haya and Amjad interviewing for the YC W18 batch. During YC Michael, Justin, Kyle, and Emmett in YC W07. OpenAI Airbnb Stripe Coinbase DoorDash Scale AI Dropbox Reddit Instacart GitLab Kalshi Replit Twitch $1.3 Trillionin combined valuation All companies Now Sam built OpenAI into a $500B company. Now Airbnb went public in 2020 at an over $100B valuation. Now Stripe is now the internet’s $107B payments backbone. Now Coinbase went public in 2021 at a $86B valuation. Now DoorDash went public in 2020 at a valuation of $39B. Now In 2025, Meta acquired 49% of Scale for over $14B. Now Dropbox had the biggest tech IPO of 2018 at a $9B valuation. Now Reddit went public in 2024 at a $6.4B valuation. Now Instacart went public in 2023 at a $10B valuation. Now GitLab went public in 2021 at an $11B valuation. Now Kalshi reached an $11B valuation in 2025. Now Replit became a leading AI coding platform valued at over $9B. Now Twitch was acquired by Amazon for nearly $1B. In 2005, Y Combinator developed a new model of startup funding. Four times a year we invest $500k in a select group of startups. They move to San Francisco for three months, where we work intensively with them to get the company into the best possible shape, before they present to a large audience of investors on Demo Day. But YC doesn’t end on Demo Day. We and the YC alumni network continue to help founders for the life of their company, and beyond. In Founders’ Words YC compresses months of growth into weeks.The sense of urgency is so infectious among founders that it becomes the most productive period in most people’s lives. It’s a community of founders that you can’t find anywhere else.It feels like having the entire world at your back—from Partners to batchmates. Being surrounded by the top 1% of founders in the world just completely resets the bar.You leave with a completely new sense of how fast ‘fast’ can be. Be in the room with … Brian CheskyAirbnb Sam AltmanOpenAI Greg BrockmanOpenAI Michael TruellCursor Paul GrahamY Combinator Guillermo RauchVercel Dylan FieldFigma Emmett ShearTwitch Tony XuDoorDash All partners were YC founders first Garry TanPosterous, S08 Co-founder of Posterous (acquired by Twitter) and Initialized Capital. Early engineer at Palantir, designed company logo. Harj TaggarAuctomatic, W07 Co-founder and CEO of Triplebyte (acquired by Karat) and Auctomatic (acquired by Live Current Media). Graduated from Oxford. Jared FriedmanScribd, S06 Co-founder of Scribd, one of the top 100 sites on the web. Harvard CS dropout. Aaron EpsteinCreative Market, W10 Co-founder of Creative Market, generating over $100M in sales for independent creators worldwide. Diana HuEscher Reality, S17 Co-founder and CTO of Escher Reality (acquired by Niantic). Shipped AR tech for Pokémon GO to 100M+ users and grew up in Chile. Gustaf AlströmerHeysan, W07 Led Growth at Airbnb for 4.5 years. Co-founder of Heysan. Previously Head of Growth at Voxer. Nicolas DessaigneAlgolia, W14 Co-founder of Algolia, a Search API used by millions of developers. PhD in Computer Science. Tom BlomfieldGoCardless, S11 Co-founder of Monzo (£500M raised, 10% UK population). Founded GoCardless. Awarded OBE in 2019. Brad FloraPerfect Audience, S11 Co-founder and CEO of Perfect Audience (acquired by Marin Software). Active angel investor and Slate contributor. Pete KoomenOptimizely, W10 Co-founder of Optimizely, grew to $100M+ ARR before acquisition. Master’s in CS from UIUC. Ankit GuptaReverie Labs, W18 Co-founder and CTO of Reverie Labs (acquired by Ginkgo Bioworks). Deep learning researcher in language, vision, and biology. Tyler BosmenyClever, S12 Co-founder and CEO of Clever (acquired for $500M). Used by 60% of US students. David LiebBump, S09 Co-founder and CEO of Bump (150M+ users, acquired by Google). Co-founder of Google Photos (1B+ users). Andrew MiklasPagerDuty, S10 Co-founder & CTO of PagerDuty (NYSE:PD), the first incident management platform and used by half of the Fortune 500. University of Waterloo & Toronto grad. Harshita AroraAtoB, S20 Co-founder of AtoB, a fintech startup worth $800M. Moved from India to SF on an O-1 visa at 16 y/o. Jon XuFutureAdvisor, S10 Co-founder and CTO of FutureAdvisor (acquired by BlackRock). Built robo-advisor platform for financial institutions. MIT EECS grad. Chris GoldaBackType, S08 Co-founder and CEO of BackType (acquired by Twitter). Launched Twitter’s Ad Center, growing revenue to over $1B. Grey BakerPincites, S23 Co-founder of Pincites (acquired by Filevine). Previously co-founded Dependabot (acquired by GitHub) and led product and engineering at GoCardless. Knowledge & News Garry Tan: Own Your Intelligence Jensen Huang: The Mindset That Built NVIDIA Sam Altman: "Never a Better Time to Do a Startup" Alexandr Wang: “This is a Once-in-a-Civilization Opportunity” Startup News The Largest Battery-Electric Plane Ever Made Has Flown For The First Time› AI code-testing startup Blacksmith's valuation jumps almost 10x in less than a year | TechCrunch› HappyRobot is worth $1.2 billion. Its founder says it’s just ‘getting started’ | Fortune› DesignArena creators raise $7.9 million to bring taste to AI models | TechCrunch› Dili Raises $21.7m from Khosla Ventures to Bring AI-Powered Assurance to America’s Infrastructure Boom› Paul Graham Essays Default Alive or Default Dead› Do Things that Don’t Scale› Be Relentlessly Resourceful› How to Get Startup Ideas› Startup = Growth› Jensen Huang: The Mindset That Built NVIDIA Sam Altman: "Never a Better Time to Do a Startup" Alexandr Wang: “This is a Once-in-a-Civilization Opportunity” Video Garry Tan: Own Your Intelligence YC's President and CEO on working memory, skill files, and why the intelligence you rent will never compound like the intelligence you own. Startup News The Largest Battery-Electric Plane Ever Made Has Flown For The First Time› AI code-testing startup Blacksmith's valuation jumps almost 10x in less than a year | TechCrunch› HappyRobot is worth $1.2 billion. Its founder says it’s just ‘getting started’ | Fortune› DesignArena creators raise $7.9 million to bring taste to AI models | TechCrunch› Dili Raises $21.7m from Khosla Ventures to Bring AI-Powered Assurance to America’s Infrastructure Boom› Paul Graham Essays Default Alive or Default Dead› Do Things that Don’t Scale› Be Relentlessly Resourceful› How to Get Startup Ideas› Startup = Growth› It's never too early to apply. We fund companies with no revenue, product, or fully baked idea. Apply Footer Y CombinatorMake something people want. Programs YC Program Startup School Work at a Startup Co-Founder Matching Resources Startup Directory Startup Library Investors Demo Day SAFE Hacker News Launch YC YC Deals Company YC Blog Contact Press People Careers Privacy Policy Notice at Collection Security Terms of Use TwitterFacebookInstagramLinkedInYoutube © 2026 Y Combinator