Accelerator · Based in San Francisco, USA
Y Combinator
The world's most influential startup accelerator.
Visit website ↗About Y Combinator
Y Combinator funds early-stage startups twice a year with a $500K standard deal in exchange for ~7% equity. Founded in 2005 by Paul Graham, YC has funded over 5,000 companies including Airbnb, Stripe, DoorDash, Coinbase, Instacart, and Reddit.
Investment profile
- Founded
- 2005
- Check size
- $500K standard deal
- Stages
- pre seed, seed
- Sectors
- AI, SaaS, Fintech, Dev Tools, Marketplace
- Geography
- Global
- Portfolio in index
- 200
- Top categories
- AI, Dev Tools, SaaS
- Most active at
- Seed, YC S24, YC W25
- Top cities
- Remote, San Francisco, Paris
How to reach Y Combinator
- Garry TanPresident & CEO@garrytan
- Michael SeibelGroup Partner@mwseibel
- Jared FriedmanGroup Partner@snowmaker
- Dalton CaldwellGroup Partner@daltonc
Notable historical investments
- Airbnb
- Stripe
- DoorDash
- Coinbase
200 portfolio companies in the index
- Scale AI
The data platform powering the AI economy
- Replicate
Run AI models with a cloud API
- PostHog
The open-source product analytics platform
- Mintlify
Beautiful documentation that writes itself
- Retool
Build internal tools remarkably fast
- Trigger.dev
Open-source background jobs for modern TypeScript apps
- Resend
Email for developers, done right
- Loops
Email for modern SaaS companies
- Dub.co
Open-source link management for modern teams
- Webflow
Build with the power of code, visually
- Brex
The financial stack for growing companies
- Deel
Global payroll and compliance for remote teams
- Paystack
Payments infrastructure for Africa
- Railway
Deploy instantly, scale infinitely, sleep soundly
- Chatwoot
Open-source customer support platform
- Krea
Real-time AI generation for creative professionals
- Rainmaker
Making droughts end
- Helicone
Open source LLM observability for production AI
- Langfuse
Open source LLM engineering platform
- Exa AI
Neural search API designed for AI applications
- Firecrawl
Web scraping API built for LLMs
- E2B
Secure code execution sandboxes for AI agents
- Highlight
Open source full-stack monitoring and error tracking
- Instant
Realtime database for modern applications
- Nango
Open source platform for product integrations
- Evidence
Open source business intelligence with Markdown and SQL
- Lago
Open source billing and metering for usage-based pricing
- Jam
One-click bug reports that developers actually love
- Activepieces
Open source business automation platform
- Windmill
Open source developer platform for scripts and workflows
- Marimo
Reactive Python notebooks you can deploy as apps
- Trim
A foundation model for physics.
- Maritime Fusion
Fusion reactors for ships
- Bystreet
Your key to the hotel market.
- PAX Markets
More alpha, less latency: exchange and HFT on one chip.
- ReJot
We turn complex API integrations into drop-in full-stack libraries
- Paratus Health
Medical Voice Agents for Patient Management
- Roark
Test, monitor, and improve your voice agents
- Spott
AI-native ATS/CRM for recruiting firms
- Reditus Space
Reusable Satellites for zero-g manufacturing
- Misprint
Robinhood for Pokemon cards
- Miyagi Labs
AI tutors for exam prep
- Outlit
Customer Context for Agents
- Harper
AI-native commercial insurance brokerage
- Nitrode
Data for reasoning agents in dynamic environments
- Bezel
Digital AI humans that model clothes for e-commerce
- Promptless
An AI teammate that automatically updates customer docs
- Bud
Agent with a computer
- Outship
Hire amazing engineers by seeing how they use AI
- YouShift
The OS for hospital workforce management
- Egress Health
Automated revenue cycle management, starting with dentists
- Mentra
Building the open source smart glasses operating system.
- Artifact
A Collaborative, AI-native IDE for Hardware Engineers
- Browser Use
Leading open-source web agent project with 50k stars in 3 months
- Ergo
AI agents and unified data layer for revenue teams
- CopyCat
AI agents built for insurance.
- Woz
Claude Code plugin that reduces token consumption and cost by 50%
- Riviera
AI Employees for Hotels
- Lopus AI
Analytics built for Growth
- Stillwind
Autonomous Electrical Engineering
- Mecha Health
Foundation models to automate x-ray analysis for radiologists
- 10x
AI Sales Teams for Dental Practices
- Toothy AI
AI for insurance verification and billing at dental clinics
- Conntour
AI to monitor thousands of security cameras.
- Vocality Health
Voice AI for medical language translation
- Dollyglot
Character.AI with real time video avatars
- Alice.tech
AI-driven exam prep
- Steinmetz
Hardware for Electric Vehicles.
- Onlook
Cursor for Designers
- Rewbi
Uses AI to increase grid-connected battery storage revenue 2x
- Fazeshift
AI agent for Accounts Receivable
- Central
Payroll, benefits, state compliance for startups
- Doublezero
Platform to build, use, and monetize fully autonomous agents
- Outerport
AI engineering scientists - search PLMs, read drawings, run simulations.
- Patched
Reliable AI for Regulated Ops
- Mica AI
Replace the humans fixing bad data
- Capitol AI
Sovereign operating system for intelligence
- Pharos
Helping hospitals identify and prevent avoidable harm using AI
- Terra
Design and sell products in minutes
- RentFlow
First Buy Now Pay Later solution for Commercial Rent
- Rastro
The fastest way to launch product catalogs
- Quetzal
LLM-first translation and internationalization for software
- Vendra
Custom Parts, Manufactured in America
- Dataleap
The world's first vibe working platform
- Ionworks
Simulation software for battery and automotive companies
- Haystack
AI review layer that decides which code changes need attention
- BeeBettor
Robinhood for sports prediction markets
- Autumn Labs
Datadog for industrial robots
- Winfunc
AI-native security engineering for mission critical codebases
- FINNY AI
The organic growth engine for financial advisors
- Lighthouz AI
Freight bill audits and AP/AR automation for brokers
- Proxis
The platform for enterprise AI agent automations
- RetroFix
Automate any workflow using plain english
- Wordware
AI agents you can rely on
- Corgi Insurance
Building an AI financial infrastructure company
- mdhub
AI-native operating system for behavioral health
- Spaceium
In-Space Refueling
- Comfy Deploy
ComfyUI for everyone on your team
- Cheers
Win local search on ChatGPT and other LLMs
- Midship
AI for SOX testing
- SimCare
AI avatars to scale healthcare training
- Arva AI
AI Agents to scale AML, KYB and KYC operations
- Affil.ai
AI Affiliate Network For Financial Companies
- Village Labs
Helping America's businesses become employee owned
- Pipeshift
Inference for real-time agents
- Keet
Authentication for AI Agents
- Oway
AI Infrastructure for America's Empty Truck Space
- Voker
The Agent Analytics Platform
- Orca Launcher
A launcher that turns Minecraft into a game platform
- Propaya
AI commercial lease abstractions and review
- The Forecasting Company
Foundation models for time series
- Soff
AI Agents for Distributors
- Zeit AI
From data to enterprise insights in just a few words
- Distro
AI co-pilot for sales reps at industrial wholesale distributors
- Biocartesian
Converting biology into digital molecular maps
- Anthrogen
Training the next generation of protein foundation models
- NetworkOcean
Build and operate underwater data centers
- Azalea Robotics
Automating airport baggage handling with robots
- Random Labs
Building long running autonomous coding agents
- Codes Health
Medical Record Retrieval with Zero Human Error
- Entangl
Find and resolve issues in data center engineering using AI
- Evolvere BioSciences
Making next-generation antibiotics that outpace bacterial evolution
- Forge
Getting companies refunds on tariffs and duties
- Adapted
AI physical therapy for athletes
- Sonauto
Create hit songs with AI
- HeartByte
GenAI Interactive story. Creator write fictions 10x faster.
- Hazel
AI-enabled procurement for government
- Ellipsis
AI code reviews and bug fixes
- Firebender
Most powerful coding agent for Android engineers
- InQuery
Intelligent Medical Record Reviews
- Zaymo
Interactive email builder for ecommerce brands
- Encore
Developer-first backend framework with built-in infra
- Hoppscotch
Open source API development ecosystem
- Wasp
Open source full-stack web framework for React and Node
- ReadMe
Beautiful, interactive API documentation
- Agno
Open source framework for multi-modal AI agents
- Beam
Serverless infrastructure for AI and ML workloads
- Twenty
Open source CRM built for modern teams
- ToolJet
Open source low-code platform for internal tools
- Trieve
Search infrastructure with hybrid retrieval for AI apps
- Turntable
Collaborative SQL notebooks for data teams
- Formbricks
Open source in-app survey and experience research
- Requestly
Browser extension and proxy for API mocking and testing
- Documenso
Open source DocuSign alternative for document signing
- Traceloop
Open-source LLM observability with OpenTelemetry
- Portkey
AI gateway and LLMOps platform for production
- Vapi
Voice AI infrastructure for developers
- Retell AI
Build, test, and deploy voice AI agents
- AssemblyAI
Audio intelligence API for developers
- Coframe
AI that continuously optimises your website copy
- Glif
Build and share AI-powered mini apps
- Infracost
Cloud cost estimates in pull requests
- SigNoz
Open-source observability — logs, metrics, traces
- Earthly
Containerised CI/CD builds that run anywhere
- Bun
Incredibly fast JavaScript runtime and toolkit
- WunderGraph
API integration platform and GraphQL federation
- Height
Autonomous project management with built-in AI
- Slope
B2B buy-now-pay-later payments
- Doppler
Universal secrets manager for teams
- Infisical
Open-source secret management platform
- Escape
API security testing and DAST for developers
- Patch
Carbon removal and climate project infrastructure
- Opus Clip
AI video repurposing for short-form content
- Replit
Code, collaborate, and deploy from your browser
- Lovable
Build full-stack web apps by describing them in natural language
- Speak
AI-powered language learning through real conversation
- Greptile
AI that reads your entire codebase to catch bugs
- Mastra
The TypeScript framework for building AI agents
- Blacksmith
2x faster GitHub Actions with zero config changes
- Bemi
Automatic audit trails for PostgreSQL without code changes
- Levels
See how food affects your blood sugar in real time
- Gigs
Launch a mobile service that runs itself
- Casca
AI loan origination that lets banks process 10x more
- Upflow
The modern accounts receivable platform for B2B
- Slash
Business banking built for internet entrepreneurs
- Roam
Buy a home by taking over a 2-3% mortgage from a seller
- Synthflow AI
No-code AI phone call agents for any business
- Induced AI
AI agents that autonomously browse the web
- Outerbase
The interface layer for your database
- Briefer
Collaborative SQL notebooks for data teams
- Row Zero
The fastest spreadsheet in the browser
- Numeral
Automated sales tax compliance for modern commerce
- Whatnot
The largest live shopping marketplace in North America
- SurrealDB
The ultimate multi-model database
- SuperTokens
Open source authentication that is 10x easier
- Umami
Simple, fast, privacy-focused web analytics
- OpenReplay
Open source session replay and debugging suite
- HyperDX
Open source observability platform
- Dittofeed
Open source customer engagement platform
- Medusa
Building blocks for digital commerce
- Saleor
Open source GraphQL-first e-commerce platform
- Open WebUI
ChatGPT-style UI for any LLM
- LiteLLM
Call 100+ LLMs with one interface
- DeepEval
The open source LLM evaluation framework
- Flowise
Drag-and-drop UI to build LLM flows
- OneUptime
Open source observability and on-call platform
- OpenObserve
Open source observability with 140x lower storage costs
- Screenpipe
Open source AI-powered screen and audio recorder
- Composio
Integration platform for AI agents
- SuperAgent
Open source AI agent platform