391 YC Companies in the S21 Batch (Summer 2021)

Y Combinator's Summer 2021 batch (S21) has 391 companies in this directory. Below is every one of them: what it does, where it is based, its status today, and a link to its YC application reconstructed in the real form, so you can read how S21 founders described their companies before they got in.

Companies
391
Top industries
B2B, Fintech and Healthcare
Top locations
San Francisco, New York and London
391 reconstructed applications

Read the YC application of all 391 companies

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The first 100 companies, top companies first

1
Abatable
AbatableCarbon markets platform and solutions
Summer 2021London, England, United KingdomActive
2
Abbot
AbbotYour Customer Success Co-Pilot
Summer 2021San Francisco, CAInactive
4
Abstra
AbstraAutomate finance operations with Python and AI
Summer 2021Rio de Janeiro, RJ, BrazilActive
5
Adaptyv
AdaptyvWe're building fully automated labs for protein engineering
Summer 2021Lausanne, VD, SwitzerlandActive
6
Adni
AdniAI career platform for healthcare workers
Summer 2021San Francisco, CAActive
7
Adravision
AdravisionAutomation for dental clinics and insurance companies.
Summer 2021Singapore, SingaporeActive

That is 10 of 391.

Every company below has its YC application reconstructed in YC Insights. Create a free account to read them all.

Read all 391 applications
12
Ahazou
AhazouPodium for local businesses in Latam
Summer 2021São Paulo, SP, BrazilActive
13
AI Tech Packs
AI Tech PacksBuild factory ready tech packs in minutes.
Summer 2021Los Angeles, CAActive
14
Akudo
AkudoIndia's first learning-focused neobank for teenagers
Summer 2021Bengaluru, KA, IndiaInactive
16
Aleph
AlephOne source of truth for financial data.
Summer 2021New York, NYActive
18
Algofi
AlgofiBuilding the new financial system
Summer 2021Inactive
19
AlgoUniversity
AlgoUniversityBuilding Job driven Virtual Tech University for India 🇮🇳
Summer 2021Hyderabad, Telangana, IndiaActive
20
AlgoViral
AlgoViralWe help high-growth startups go viral on autopilot
Summer 2021London, United KingdomActive
21
Amenli
AmenliOffers insurance to customers in a convenient & transparent way
Summer 2021Cairo, Cairo Governorate, EgyptActive
23
Ananya Health
Ananya HealthPortable cryoablation to prevent cervical cancer
Summer 2021San Francisco, CAActive
24
Ancana
AncanaMarketplace to buy managed vacation homes through fractional ownership
Summer 2021Mérida, Yuc., MexicoActive
25
AOA Dx
AOA DxBlood Test for Early Detection of Ovarian Cancer
Summer 2021Denver, COActive
26
Apollo
ApolloThe card that rewards you with stock
Summer 2021San Francisco, CAInactive
27
AppX
AppXAppX helps social media creators launch their own mobile apps.
Summer 2021New Delhi, DL, IndiaActive
29
Archbee
ArchbeeTURN STATIC DOCS INTO INSTANT ANSWERS
Summer 2021Bucharest, Bucharest, RomaniaActive
30
Arengu
ArenguBuild frictionless signup flows in minutes
Summer 2021A Coruña, GA, SpainAcquired
31
ARQ
ARQThe global financial platform for affluent consumers in the Americas.
Summer 2021London, United KingdomActive
32
Arrow
ArrowModern Checkout Platform for D2C brands in Southeast Asia
Summer 2021Singapore, SingaporeActive
33
Artillery
ArtilleryThe complete production quality platform. AI-powered E2E testing,…
Summer 2021Limerick, County Limerick, IrelandActive
34
aSim
aSimBuild and share apps with friends
Summer 2021Seattle, WAActive
35
Astek Diagnostics
Astek DiagnosticsOne-hour antibiotic sensitivity testing
Summer 2021Baltimore, MDActive
36
Atlas
AtlasOperating system for restaurants, focusing on Southeast Asia
Summer 2021Singapore, SingaporeActive
37
Atmana
AtmanaApps to control technology addictions/ helping startups hire engineers
Summer 2021Dubai, Dubai, United Arab EmiratesActive
38
Aviator
AviatorGoogle-level engineering productivity suite
Summer 2021San Francisco, CAActive
39
Awesomic
AwesomicGet matched with top 1% of talents in 24h
Summer 2021San Francisco, CAActive
40
Baraka
BarakaGrow Your Wealth With Baraka
Summer 2021Dubai, United Arab EmiratesActive
41
Baubap
BaubapSmart micro financing for everyone
Summer 2021Mexico City, CDMX, MexicoActive
42
Beau
BeauWorkflows for repetitive customer-facing tasks
Summer 2021Barcelona, CT, SpainActive
43
Beeper
BeeperOne chat app to rule them all
Summer 2021Palo Alto, CAAcquired
45
Bite Ninja
Bite NinjaRemote labor for restaurants
Summer 2021Memphis, TNActive
48
BLUUMBIO
BLUUMBIOWe make bacteria and plants that clean up pollution.
Summer 2021San Francisco, CAActive
52
Bree
BreeChime for Canada, starting with cash advances
Summer 2021Vancouver, BC, CanadaActive
53
Brite
BriteSoftware that helps employees pick their employee benefits.
Summer 2021Salt Lake City, UTActive
54
Buoyant Aero
Buoyant AeroBringing back blimps
Summer 2021New York City, NYActive
55
Buró de Ingresos
Buró de IngresosThe Work Number for LatAm
Summer 2021Mexico City, CDMX, MexicoActive
60
Cache
CacheOnline convenience stores fulfilled by tiny, automated dark stores.
Summer 2021San Francisco, CAInactive
61
Café
CaféYour Workplace Engagement Hub
Summer 2021Paris, Île-de-France, FranceActive
63
Canopi
CanopiAPI to measure and eliminate carbon emissions
Summer 2021San Francisco, CAInactive
64
Carbonfact
CarbonfactDecarbonizing the fashion industry
Summer 2021Paris, Île-de-France, FranceActive
66
Cartpanda
CartpandaGlobal online sales platform
Summer 2021São Paulo, SP, BrazilActive
67
Catena Biosciences
Catena BiosciencesUsing protein coupling to build new therapies
Summer 2021Berkeley, CAActive
68
CellChorus
CellChorusThe dynamic single-cell analysis company
Summer 2021Houston, TXActive
69
Cero
CeroAutomated communication between hospitals and patients in Latam
Summer 2021Santiago, Santiago Metropolitan Region, ChileActive
70
Charge Robotics
Charge RoboticsRobots that build solar farms
Summer 2021Oakland, CAActive
71
Chari
ChariB2B e-commerce and fintech platform for traditional proximity stores
Summer 2021Casablanca, Casablanca-Settat, MoroccoActive
72
Chipax
ChipaxQuickbooks for SMBs in Latam
Summer 2021Santiago, Santiago Metropolitan Region, ChileActive
73
Cloudanix
CloudanixCloud and Container Security Platform
Summer 2021Sunnyvale, CAActive
75
Coast
CoastDemo Platform for API-First Companies
Summer 2021New York, NYActive
76
Cococart
CococartEmpowering local businesses to sell online.
Summer 2021Singapore, SingaporeActive
77
Coinrule
CoinruleCoinrule Automates Your Crypto and Stock Investments
Summer 2021London, England, United KingdomActive
78
CoLoop
CoLoopAI Copilot for insights & strategy
Summer 2021London, England, United KingdomActive
79
Comet Health
Comet HealthDigital platform for pelvic floor physical therapy
Summer 2021Palo Alto, CAInactive
80
Commery
CommeryMarketplace to lease commercial real estate
Summer 2021New York, NYInactive
83
Contalink
ContalinkWe help Accountants automate work and serve their customers online
Summer 2021Monterrey, N.L., MexicoActive
85
Coulomb AI
Coulomb AIBattery Observability Platform for Electric Vehicles
Summer 2021Bengaluru, KA, IndiaActive
87
Crew
CrewNext Gen ATS/CRM for Modern Recruitment Agencies
Summer 2021Paris, Île-de-France, FranceActive
88
Cumbuca
CumbucaBare-metal access to Brazil's Open Finance and Pix systems
Summer 2021São Paulo, SP, BrazilActive
89
Customily
CustomilyMaking it easy to sell personalized products online.
Summer 2021St. Louis, MOActive
90
Dailybot
DailybotMake all team work visible - people and AI agents
Summer 2021Remote, ORActive
91
Datlo
DatloDatlo helps companies increase sales and expand through data
Summer 2021Maringá, PR, BrazilActive
93
Deskimo
DeskimoWorkspaces on demand, paid by the minute.
Summer 2021Singapore, SingaporeActive
95
Digistain
DigistainPioneering Breast Cancer Diagnostics for a Healthier Tomorrow
Summer 2021London, England, United KingdomActive
96
Dime
DimeInstant E2E tests for your website
Summer 2021San Francisco, CAInactive
97
Dot
DotChat with your Data Warehouse
Summer 2021Berlin, Berlin, GermanyActive
98
Dots 💸
Dots 💸Developer friendly drop in payouts infrastructure
Summer 2021San Francisco, CAActive
99
Double
DoubleWe make software for bookkeepers.
Summer 2021New York, NYActive
100
Echoes HQ
Echoes HQMeasure and communicate engineering activity
Summer 2021Amsterdam, NH, NetherlandsActive

The other 291 companies

Every remaining company in this list, A to Z. Each link opens the company's public page.

EncuadradoEndlaEnerjazzEnsoEpinomaEpsilon3Equipt HealthEvidenceEvidently AIExaExamediFastFarmaFemale InvestFerveretFiladdFiltaFingo AfricaFirstIgniteFirstQuadrantFitiaFloatFloatpays IncFlow ClubFlowboFlowlyflukeForageForage MailFormanceFreteriumFrontPageGamerPayGenomelinkGenuityGeostarGlitziGobillionGoodkindGovlyHarmonic DiscoveryHedgehogHeimdalHEO RoboticsHeraHeyChargeHilosHireboltHitPayHive HealthhotglueHudson Labs (formerly Bedrock AI)Humane GenomicsHyperHyperbrowserHypercontextHypercoreHyperseedHyperTraderidemeuminaiInferInfinaInfiuss HealthInflowInstacropsInstaKinIntellectInversion SpaceIvellaIvy HomesJABUJestorJovianJupeKaiPod LearningKalam LabsKapacity.ioKarbon CardKayaKeyriKindamagicalKiwi BiosciencesKoddaKodexKonta.comKoshexKuriosLagolapzoLariat DataLaudableLegion HealthLemFiLevelLevoLevroLightlyLitnerdLiv LabsLobbyLocaleLootRushLuableLuminateMableMach9MadEatsMailmodoMakani ScienceMalgaMalloc IncmarketfeedMarooMarqVisionMatidor.comMatrubialsMecho AutotechMedium BiosciencesMemboMentorcamMentumMergentMeticulousMicro MeatMilky Way AIMindFiMindmeshMindstate Design LabsMineMiniloopMixrMobileBoostMomo MedicalMonetMontoMoving PartsNasdiscNashNeodocsNexusNino FoodsNolocoNomodNovatrODWENOdys AviationOkaniOnebriefOneSchemaOneShopOneStopKitchenOnfolkOnsite ProOpenlayerOpkitOrderlioutloud.aiOutput BiosciencesPactimaPaletteHQPallaPandaiParallel BioPatternsPayflowPayhippoPAYZEPerfektoPhykosPide DirectoPideakyPillarPipekitPirouette PharmaPlaiPlanet A FoodsPluggyPortão 3PositionalPotionPromakhos TherapeuticsPropReturnsProtegoProtex AIPylonQuestRedbeanReframe (Glucobit)RendaloMaqReploRepoolREPROSENTRevery AIRevolve SurgicalRinseRivia.AIRMFGRootlyRuta HealthRuth HealthSafeBeatSafer ManagementSalaryBookSalaryBoxSatsumaScispotScratch DataSecodaSenpAI.GGSensible BiotechnologiesSentiyenSequinSFA TherapeuticsShapeShimmerShipBluSigloSigmaOSSirkaSitennaSlashSleekSlopeSnapCalorieSocoSolarMenteSpark StudioSpokenSproutfiSquire.aiStardexStepfulStipopStorylaneStownestStrideQStrive MathStudyStreamSully.aiSuperwallSupliasSwipeSynderTablevibeTAGTalentdropTalus BioTarsalTavusTelivyTelmaiTenykstestRigorThe BreakawayTherifyTitipkuTokuTrackChainTransAstra CorporationtriiTrussTuli HealthTurion SpaceUnion54V-Flow MedicalVarosVedaBioVerano HealthVerdeVerihubsVibe KanbanVincoVitalStrataVogentWabiWarpBuildWarpfyWarrantWaterplanWhalesyncWhalyWritesonicYemaachi BiotechnologyYummyZageZaz OSZeit MedicalZenZensorsZoios.Zuma

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About this list

This list is part of Round Funded, an investor database and outreach platform for founders. It covers 60,000+ active VCs, angels, family offices and accelerators with verified contacts, lets you send pitches from your own Gmail, and includes a free Data Room for your raise.

Frequently Asked Questions

How many Y Combinator companies are in the Summer 2021 batch?

This directory lists 391 YC companies in the Summer 2021 batch, out of 6,207 across every batch since 2005. The count updates when the directory is refreshed, and every one of them is on this page with a link to its public profile.

Are the YC applications on these pages real?

No. YC keeps submitted applications private. Every application linked from this list is a reconstruction: the real YC form questions, answered from the company's public data. The Company section is free on each page; the rest opens in YC Insights.

How do I use this list when applying to YC?

Pick five companies on this page whose product is closest to yours, read their reconstructed applications side by side in YC Insights, and note how each answers the same question. Then write your own answers to that standard.

Where does this data come from?

From YC's public company directory, refreshed by batch, with each company's status, industry and location as YC reports them. Round Funded adds the reconstructed application and the founder profiles; nothing private is published.

What is Round Funded?

Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.