YC ALUMNI DATABASE
List of YC Companies & Alumni, by Batch.
We track 87 YC companies with full founder stories, rejection case studies, or documented pivots. Grouped by batch, newest first. New companies added every week.
What's in here
Every row links to source-verified material — a long-form founder story, a rejection case study, or both. Want the raw data on every YC company ever? See our databases.
Famous YC Companies
The best-known Y Combinator alumni — every one has a full source-linked founder story on YC Insights.
Batch S19
3 companiesPippin / Rent the Backyard
storyBrian Bakerman
Two Carnegie Mellon engineering students noticed that California had quietly passed laws making it dramatically easier to build homes in backyards — and decided to build a factory to exploit that window at scale. They got into YC, raised funding, built a real factory in Oakland, reached $10M+ in contracted revenue — and then ran out of money before they could reach profitability.
Odeko
storyDane Atkinson
A man who had already been CEO of six companies — including Squarespace — walked into YC at 46 with a gut instinct about coffee shops, watched COVID erase every dollar of revenue he had, then rebuilt from zero to $150M in two years by doing the one thing every software founder avoids: delivering physical goods overnight.
Gather (gather.town)
storyPhillip Wang
A team of recent college graduates tried six different product ideas — wristwatches, robots, tablet apps, VR — failed at all of them, pivoted when a pandemic hit, and accidentally built the most human-feeling video platform on the internet by making it look like a video game.
Batch W17
1 companyBatch W15
1 companyBatch W14
2 companiesCruise
caseKyle Vogt, Daniel Kan
Cruise entered YC W14 trying to retrofit autonomy onto regular cars. The industry called it impossible. GM bought them 2 years later.
Flexport
caseRyan Petersen
Flexport pitched 'software for freight forwarders' at YC W14. Every logistics insider said the industry would never digitize. Ryan kept going.
Batch S13
1 companyBatch S12
3 companiesCoinbase
caseBrian Armstrong, Fred Ehrsam
Coinbase nearly didn't make it into YC S12 — Brian Armstrong's original co-founder was rejected mid-interview. Brian went solo into the batch.
Instacart
caseApoorva Mehta
Apoorva failed at 20 startups before Instacart. He applied to YC S12 after the deadline. He got in by delivering PG a six-pack via his own app.
Zapier
caseWade Foster, Bryan Helmig, Mike Knoop
Zapier's first YC application was rejected. They shipped a working product, applied again to S12 with paying users, and got in.
Batch W12
1 companyBatch S11
1 companyBatch W10
1 companyBatch S09
2 companiesStripe
storyPatrick Collison
In 2010, accepting a payment online required a merchant account, a payment gateway, weeks of paperwork, and PCI compliance. The Collison brothers shipped a competitor that worked in seven lines of curl.
Stripe
storyPatrick Collison
Two Irish brothers, already teen millionaires from their first exit, walked away from comfort and asked one quiet question — "Why is it so hard to accept money on the internet?" — then spent the next decade turning that question into the financial infrastructure of the modern web.
Batch W09
1 companyBatch S08
4 companiesPosterous
storySachin Agarwal
Three Stanford engineers built the world's simplest blogging platform — post anything just by sending an email — grew it to 15 million users, then watched it unravel the moment they stopped trusting simplicity. One founder went on to run Y Combinator. The story of Posterous is equal parts inspiration and cautionary tale.
Poll Everywhere
storyJeff Vyduna
Three Deloitte consultants were so tired of watching audiences zone out during their own presentations that they built a text-message voting tool to keep people awake — then discovered they'd accidentally created the product that would kill a $15,000-per-unit hardware industry.
Cloudant
storyMichael Miller
Three MIT physicists were moving petabytes of data from the world's largest physics experiment and couldn't find a single tool that worked at that scale. So they built one — and accidentally created the cloud database infrastructure that IBM eventually paid to own.
BackType
storyChristopher Golda
Two Canadian engineers from Toronto — who had already built and failed with one startup — walked into YC Summer 2008 with a simple idea about blog comments, and walked out having quietly invented the infrastructure that powers real-time social data analytics at Twitter scale.
Batch W08
9 companiesTrigger.io (originally named "Trigger")
storyAmir Nathoo
Three Cambridge and MIT-educated engineers left corporate jobs at IBM to build the simplest way for web developers to create native mobile apps — got into YC, raised money, grew fast, and then watched the entire HTML5-vs-native debate kill their market before they could outlast it.
Snaptalent
storySumon Sadhu
A Oxford-educated biochemist dropped his PhD, got headhunted by Paul Graham into one of the earliest YC batches, built the world's first IP-targeted developer job ad network, made $30K before Demo Day — and then shut it all down two years later because he was five years too early for the market he was trying to create.
RescueTime
storyTony Wright
While every other startup was chasing hockey-stick metrics, three Seattle founders quietly built a product on evenings and weekends to answer one brutally honest question: "Where does all my time actually go?" — and in doing so, created one of the most enduring productivity tools the internet has ever seen.
Omnisio
storyRyan Junee
Three Australians with engineering degrees, no prior exits, and no Silicon Valley network walked into YC with a single powerful insight — online video is a static, one-way broadcast when it could be a living, interactive medium — and sold that insight to Google less than a year later.
Kirkland North (product: PlayTurf / Turf)
storyGabe Smedresman
A Yale student accidentally built a game so addictive that 25% of his entire campus played it — then turned that accident into a YC-backed startup, only to discover that virality and a business are two very different things.
Machine Zone, Inc. (formerly Addmired)
storyGabriel "Gabe" Leydon
A man who started his company while collecting unemployment benefits — and who came from the dying world of coin-op arcade machines — looked at the iPhone and saw something everyone else missed: not a phone, not a gaming device, but a virtual supermarket in everyone's pocket. He was right, and it made him a billionaire.
Insoshi
storyMichael Hartl
Two Harvard-educated physicists with PhDs built the "WordPress for social networks" in Ruby on Rails, got into YC, became one of GitHub's most-forked repositories, nearly raised a significant funding round — and then watched the 2008 financial crisis kill the deal in October. The company shut down. The founder wrote a tutorial instead. That tutorial made $750,000 and became the most widely read Rails resource in the world.
A Thinking Ape (ATA)
storyKenshi Arasaki
Three Canadian engineers quit Amazon, got into YC with a chat app, watched it fail to take off — then noticed something unexpected in their own data: people were using their chat rooms to form war clans. They ignored everything they'd built and followed the community. That pivot became one of Canada's most profitable mobile game studios, built entirely without venture capital.
280 North, Inc.
storyFrancisco Tolmasky
Three USC college friends — two of whom had built parts of the original iPhone — got so frustrated with how terrible web development was that they secretly built a better version of Apple's own desktop toolkit for the web, launched it as open source, and were acquired by Motorola for $20 million just two years later.
Batch S07
6 companiesDropbox
storyDrew Houston
Drew Houston couldn't get product/market signal because nobody understood what Dropbox did. So in 2008 he made a screencast aimed at one community — and woke up with 70,000 new users.
Songkick
storyIan Hogarth
A literature graduate, a Cambridge-trained engineer, and a best friend from university — none of them startup people — solved a problem so personal and obvious that they almost talked themselves out of applying. Songkick became the world's second-largest concert platform by refusing to outsmart itself: they just built what one of them desperately wished existed.
SocialPicks
storyWeiting Liu
A Taiwanese immigrant and Stanford engineer watched Mark Zuckerberg speak and thought, "It's not impossible to build something big right after school" — then spent the next two years trying to do exactly that, turning stock market communities into a social graph before anyone called it fintech.
iJigg (later Top440)
storyShadab Farooqui
A 25-year-old from Bombay who never planned to be a founder accidentally built one of the internet's first social music platforms, got into YC, scaled to 5 million users — then watched the music industry kill everything he built.
AppJet, Inc. (pivoted to → Etherpad)
storyAaron Iba
Three ex-Google engineers left stable, prestigious jobs to build a developer platform nobody used — then accidentally invented real-time collaborative editing on a Friday afternoon, watched that side project become the real company, and got acquired by Google two years later. The thing they built to demo the product they failed at became one of the most influential pieces of software infrastructure in the modern internet.
Anywhere.FM
storySachin Rekhi
Paul Graham told them he hated their idea — then funded them anyway, on one condition: come up with a new one. What happened next is one of YC's clearest lessons about what actually gets you in: the team, not the idea.
Batch W07
7 companiesZenter
storyWayne Crosby
Two PhD engineers — one applying to YC the same night his wife told him she was pregnant — built a browser-based PowerPoint killer in a few months, got acquired by Google, and accidentally created the tool that over a billion people now use to present their ideas to the world.
Weebly
storyDavid Rusenko
Three college kids built a website builder as a class project, applied to YC with one hour left before the deadline, got told their idea was "the worst ever heard" at their first public demo — and spent the next 12 years quietly proving everyone wrong on the way to a $365 million exit.
Tsumobi
storyJoshua Wilson
Two MIT undergrads on leave of absence got into YC in 2007, raised seed funding from the legendary Ron Conway, and built a technically prescient mobile infrastructure product — one year before the iPhone App Store made their entire approach obsolete overnight.
Octopart
storyAndres Morey
Three physics PhD students were so frustrated searching for electronic components for their lab experiments that they built a search engine for it — dropped out of grad school, nearly went broke during the 2008 financial crisis, refused to quit, and turned a boring niche into a half-million-user platform that got acquired eight years later.
Heysan
storyGustaf Alstromer
A team of Swedish founders shipped the right product two years too early, built 1 million users without cracking growth, got acquired quietly — and then the CEO spent the next decade becoming one of the world's foremost experts on the exact problem that killed his company: distribution.
Dropbox
storyDrew Houston
A MIT grad forgot his USB drive on a 4-hour bus ride, spent the trip building a solution instead of complaining about the problem — got rejected by YC once, almost didn't apply again, made a bedroom demo video at 3am that went viral, found a co-founder in 2 weeks, and built the company that became the first YC startup ever to go public.
Twitch (then Justin.tv)
caseJustin Kan, Emmett Shear, Michael Seibel, Kyle Vogt
Justin.tv was a YC company that flatlined. They quietly built a 'gaming' subdirectory that ate the whole company.
Batch S06
3 companiesThinkature
storyDrew Harry
Drew Harry built a real-time online whiteboard in 2006 that worked — got into YC, got press, got users — and still shut down four years later. The lesson isn't about the product. It's about building something people admire vs. building something people pay for.
Shoutfit
storyChris Smoak
A Carnegie Mellon engineer in 2006 saw that people were passionate about their personal style but had nowhere online to share it — built a fashion social network three years before Instagram existed, got into YC, couldn't crack user retention, pivoted twice, shut it down, and used everything he learned to do YC two more times with bigger swings.
Jamglue
storyGautam Jayaraman
Four college friends with a shared love of music and a question — "Why isn't there a YouTube for audio?" — built one of YC's earliest consumer products: a browser-based remix platform that grew to 75,000 members, ran remix contests with major artists, and then quietly shut down — teaching its founders lessons that funded everything they built next.
Batch W06
1 companyBatch Summer 2007
7 companiesZumoDrive (by Zecter, Inc.)
storyDavid Zhao
Three engineers from Microsoft and Amazon saw the same broken problem every day at their desk jobs — carrying content between devices was painful — and instead of complaining about it, they quit, applied to YC, pivoted once, and built the technology that powered HP's entire netbook line before Dropbox was even a household name.
Splashup (originally named Fauxto, incorporated as Faux Labs, Inc.)
storyDave Brushinski
Dave Brushinski built the world's first browser-based Photoshop-like editor in 2006 — layers, brushes, effects, the whole thing — before anyone else had proved it was possible. He got into YC, got press, got users. Then the market caught up, better-funded competitors arrived, Flash died, and Splashup quietly closed. The idea was right. Almost everything else was a lesson.
Fuzzwich / Habit Industries
storyRob Fitzpatrick
Two college friends pitched a video game studio to YC, pivoted the idea mid-interview when the partners tore their business plan apart, got funded anyway, built an animation platform used by Sony and Aardman, raised from top-tier investors — and still shut down. Then Rob Fitzpatrick turned the entire painful experience into The Mom Test, a book that has saved thousands of startups from making the exact mistakes he made.
Disqus
storyDaniel Ha
Two college friends, bored in computer science classes and building side projects for fun, accidentally created the internet's default comment system — not by chasing a big idea, but by following the one small feature that people actually showed up to use.
ContestMachine
storySavraj Singh
Three Microsoft engineers left their stable jobs, got into YC Summer 2007 alongside Dropbox and Arash Ferdowsi, built a real product that actual beauty bloggers loved — then ignored the most important warning Paul Graham ever gave them, and learned the hard way that being technical is not enough.
Blue Frog Gaming
storyMatt Maroon
A professional poker player from Akron, Ohio walked into Y Combinator with a fantasy sports gambling idea, got funded, watched that idea fail — then accidentally built the largest virtual universe on Facebook by launching a side project to promote a product nobody wanted.
Biographicon
storyEthan Herdrick
Two programmers with a genuinely interesting idea — "Wikipedia, but for every person on earth, not just famous ones" — got into YC, built the product, launched it publicly, and watched it die in silence five months later. Not because the idea was wrong, but because they launched a community product with nobody in the community.
Batch Winter 2007
3 companiesVirtualmin
storyJamie Cameron
Two open-source veterans who had been quietly building the world's most-downloaded Linux admin tool for a decade realised they'd given away a million-dollar product for free — and YC gave them the framework to finally charge for it.
Buxfer
storyShashank Pandit
Three Indian PhD students at Carnegie Mellon built a shared-expense tracker out of sheer frustration with IOUs on a refrigerator — got into YC, grew to 100,000 users, watched both co-founders leave for Facebook, and then one of them quietly rebuilt it alone into a profitable, privacy-first personal finance tool still running 18 years later.
Auctomatic
storyHarj Taggar
Four young founders — two Oxford law students and two Irish teenage prodigies — walked into YC with the wrong idea, pivoted within three weeks, built something real, and sold it for $5 million before any of them turned 25. One of them became CEO of Stripe. One became a YC Managing Partner. One built a $450M company. One launched a VC fund. Auctomatic wasn't the destination — it was the launchpad.
Batch —
1 companyBatch Winter 2008 (one of the earliest cohorts — only 21 companies)
1 companyBatch Summer 2005 — YC's Very First Batch Ever
2 companiesTextPayMe
storyPhilip Yuen
A Paul Graham essay kept a Microsoft engineer up at night, pushed him to quit his stable job, fly across the country to a lecture, get into YC's first-ever batch with the wrong idea — then pivot to the right one mid-batch, get acquired by Amazon within a year, and plant the seed for what eventually became every P2P payment app you use today.
Kiko (Kiko Software)
storyJustin Kan
Kiko failed in 12 months, got killed by Google, and was sold on eBay for $258,100 — and it's one of the most important startup stories in YC's entire history, because the two founders who built it went on to create Twitch, which sold to Amazon for $970 million. This is the story of what a "failed" startup actually looks like — and why failure is often just a slow-burning launchpad.
Batch Winter 2006 — one of YC's earliest ever cohorts
1 companyBatch Summer 2006
1 companyBatch Summer 2008
2 companiesSocialbrowse
storyZack Garbow
Two engineers built a browser extension to socialize the web in 2008, watched it quietly die, and then Dave Fowler took every lesson from that failure straight into YC a second time — where he built Chartio, made Forbes 30 Under 30 twice, and eventually sold to Atlassian.
Scoopler Inc. → Pivoted to JustSpotted
storyAJ Asver
Two immigrant engineers — one from Sri Lanka via MIT, one from Oxford — built one of the world's first real-time search engines, got into YC when almost no one understood what real-time search meant, pivoted hard when the market shifted under them, and ended up inside Google helping build the future of social. It wasn't a straight line. It was a masterclass in staying technically relevant while the world caught up.
Batch Winter 2006 (One of YC's earliest-ever batches)
1 companyBatch Summer 2005 — The Very First YC Batch Ever
1 companyBatch Summer 2006 (YC's 2nd year — one of the earliest batches ever)
1 companyBatch Summer 2005 (Asynchronous investment — did not participate in standard YC cycle)
1 companyBatch Summer 2006 — Inaugural YC Class
1 companyBatch Summer 2005 — The very first YC batch ever funded
1 companyBatch Winter 2006
1 companyBatch Summer 2006 (one of YC's earliest classes)
1 companyBatch Summer 2007 (5th ever YC batch)
1 companyBatch Summer 2005 — YC's very first batch ever
1 companyBatch Winter 2008
7 companiesMightyQuiz
storyBen Silbermann
A doctor's son from Iowa who was never supposed to be a founder, never learned to code, and watched his first YC company quietly die — then used everything he learned from that failure to build one of the most-used websites on the internet.
Mixwit
storyRadley Marx
Two designers built the most loved online mixtape of 2008, got into YC, grew a passionate user base — and then shut down because they were too honest to pretend the music industry would leave them alone.
Ninite (formerly BaseShield / Secure By Design Inc.)
storyPatrick Swieskowski
Two open-source hackers were so fed up with the ritual humiliation of reinstalling Windows — the toolbar junk, the "click next 47 times" installers, the adware hiding inside free software downloads — that they built the cure. Fifteen years later, it still runs with 2 people and serves NASA.
Joberator
storyJorge Ortiz
A Stanford-trained engineer looked at the STEM hiring market in 2007, saw a broken connection between brilliant talent and the companies that needed them most, got accepted into YC to fix it — and in doing so, built the skills and credibility that launched a career at three of Silicon Valley's most important companies.
Heroku
storyJames Lindenbaum
Three developers at a boring consulting shop in Los Angeles fell in love with Ruby, went to a conference that felt like a religious awakening, and built a product nobody wanted — until they pivoted to what everyone was secretly already using them for. The result: a $212M exit on $13M raised, and a deployment command — `git push heroku main` — that a generation of developers will never forget.
FathomDB
storyJustin Santa Barbara
A Cambridge-educated engineer working odd jobs in London spotted a problem that the entire cloud industry would eventually validate — databases were still being run like it was 1995 — got into YC in 2008, built the world's first relational Database-as-a-Service, and then watched Amazon build the same thing six months later. FathomDB's story is not one of failure — it's one of being exactly right, at exactly the wrong time, against exactly the wrong competitor.
BitSample → Ninite
storyPatrick Swieskowski
Two solo founders walked into YC W08 with two different ideas, met each other, killed both ideas, failed at an app store, and accidentally built one of the most reliable and beloved utility tools on the internet — with a team of just two people, forever.
Batch 2009
1 companyBatch Summer 2005 — YC's very first batch, ever
1 companyBatch Winter 2006 (YC's very second batch ever)
1 companyBatch Winter 2006 — one of YC's earliest cohorts
1 companyBatch Summer 2007 (One of the first 5 YC cohorts — same batch as Disqus)
1 companyKeep exploring
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Guide
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The $500K deal, 3-month program, and acceptance rate — in plain English.
Stories
Founder Stories →
70+ deeply-reported founder journeys from YC alumni.
Database
YC Rejection Database →
32+ founders who got rejected — then built billion-dollar companies.