Y Combinator Portfolio

YC-Backed Companies

5,949 Y Combinator portfolio companies tracked in the Altss database. For each company, Altss surfaces which family offices have co-invested alongside YC.

Winter 2026

(199 companies)
10x Science logo
W26

10x Science

The AI-native platform for next-generation protein characterization.

21st logo
W26

21st

Infrastructure and UI building blocks for the agentic internet

ARC Prize Foundation logo
W26

ARC Prize Foundation

AI benchmarks that measure general intelligence and inspire new ideas

Aemon logo
W26

Aemon

The Forward-Deployed AI Research Engineer

Agentic Fabriq logo
W26

Agentic Fabriq

Okta for Agents.

Alt-X logo
W26

Alt-X

Automation for institutional-grade financial modeling in Excel

Approxima logo
W26

Approxima

Your software should build itself.

Ashr logo
W26

Ashr

Automated Multi-Modal Testing for Agents

Asimov logo
W26

Asimov

Real-world human movement data for humanoid robots

Aurorin CAD logo
W26

Aurorin CAD

Claude code for Mechanical Engineers

AutoSitu logo
W26

AutoSitu

AI-native workspace for development plan reviews

Autumn AI logo
W26

Autumn AI

Stalk your prospects at scale.

Avoice logo
W26

Avoice

Harvey for Architecture

AxionOrbital Space logo
W26

AxionOrbital Space

Foundation models for 24/7 Earth Observation

Axis logo
W26

Axis

An AI Copilot for Trading Desks

Balance logo
W26

Balance

Full-Stack AI Accounting

BaseFrame logo
W26

BaseFrame

Detect what AI can automate for your team

Beacon Health logo
W26

Beacon Health

AI Employees for Primary Care

BeeSafe AI logo
W26

BeeSafe AI

Frontier AI Defenses for Social Engineering Attacks

Beyond Reach Labs logo
W26

Beyond Reach Labs

Space solar arrays that grow to the size of a football field in orbit

Bidflow logo
W26

Bidflow

AI Takeoffs for Electrical

Booko logo
W26

Booko

Dynamically pricing the whole economy.

Bubble Lab logo
W26

Bubble Lab

Prompt once, automate forever.

Burt logo
W26

Burt

AI teammates for logistics

Button Computer logo
W26

Button Computer

Button is the wearable AI that can talk.

Byteport logo
W26

Byteport

Global upload acceleration for 1GB-100TB files.

Cajal logo
W26

Cajal

Scaling formal verification to accelerate scientific discovery

Canary logo
W26

Canary

The first AI QA engineer that understands your code

Captain logo
W26

Captain

Give AI agents accurate knowledge search that scales

Cardboard logo
W26

Cardboard

Agentic video editor

Cardinal logo
W26

Cardinal

AI Platform for Precision Outbound

Caretta logo
W26

Caretta

Realtime AI for Sales Calls

Carrot Labs logo
W26

Carrot Labs

AI Cost Management: Track and attribute AI spend across every provider

Carson logo
W26

Carson

Carson is a desktop AI app that generates custom, sharable workspaces

Cascade logo
W26

Cascade

Distilling Proprietary Intelligence

CatchBack Cards logo
W26

CatchBack Cards

The most thrilling way to create and rip digital collectible packs

CellType logo
W26

CellType

The agentic drug company. We simulate human biology.

Chamber logo
W26

Chamber

The AIOps Agent for ML Teams

Chasi logo
W26

Chasi

AI Revenue Engine for the Equipment Industry

ClaimGlide logo
W26

ClaimGlide

AI automated prior-auths for private medical practices

CodeWisp logo
W26

CodeWisp

Anyone can create real games with AI

Cofia logo
W26

Cofia

AI automations that implement themselves

Compresr logo
W26

Compresr

LLM context compression for better accuracy

Condor Energy logo
W26

Condor Energy

Software for enterprise energy procurement.

Confluence Labs logo
W26

Confluence Labs

AI models that learn from experience

Congruent logo
W26

Congruent

AI native radars for self-driving cars

Constellation Space logo
W26

Constellation Space

AI operating system for mega-scale satellite networks.

Copperlane logo
W26

Copperlane

Agentic Mortgage Origination

Corelayer logo
W26

Corelayer

AI on-call engineer for data-heavy, regulated industries

Corvera logo
W26

Corvera

The context layer for AI-native CPG brands

Crosslayer Labs logo
W26

Crosslayer Labs

Protect, monitor and defend your Internet presence

Crow logo
W26

Crow

AI for Commercial Real Estate

Cumulus Labs logo
W26

Cumulus Labs

The Fastest Multimodal Inference OS

DAIVIN! logo
W26

DAIVIN!

Tankless Dive Gear - Breath Autonomy at Sea, Land & Space

Datoric logo
W26

Datoric

Responsibly sourced data for multimodal AI

Didit logo
W26

Didit

Infrastructure for identity and fraud.

fintech · Spain

Ditto Biosciences logo
W26

Ditto Biosciences

Evolutionary intelligence for autoimmune disease

Docura Health logo
W26

Docura Health

AI-Native Med-Legal Firm

Doomersion logo
W26

Doomersion

Doomscroll to learn languages

EigenPal logo
W26

EigenPal

AI Document Workflows for Enterprises

Emdash logo
W26

Emdash

Open-source Agentic Development Environment

End Close logo
W26

End Close

AI powered reconciliation for high-volume payments companies

Envariant logo
W26

Envariant

Interpretability and reasoning infra for foundation models.

Eos AI logo
W26

Eos AI

Autonomous OS for healthcare

Fed10 logo
W26

Fed10

AI agents that replace your policy consultants

Fenrock AI logo
W26

Fenrock AI

AI agents for banking back office

Fern logo
W26

Fern

Enabling physical AI at scale.

Fixture logo
W26

Fixture

An AI-first CRM built for Startups

Foreman logo
W26

Foreman

Keeping contractors on the job site, not behind a desk.

Fort logo
W26

Fort

Strength Tracking Wearable

Forum logo
W26

Forum

The first exchange to trade on attention.

FullSeam logo
W26

FullSeam

AI agents for corporate accounting teams

Galactic Resource Utilization Space, Inc. (GRU Space) logo
W26

Galactic Resource Utilization Space, Inc. (GRU Space)

Moon Hotel -> The Intergalactic Construction Company of Earth

General Astronautics logo
W26

General Astronautics

Robotics for Space R&D

General Legal logo
W26

General Legal

The AI native law firm for growth stage companies

Glue logo
W26

Glue

The Interface Design Canvas for AI agents

Grade logo
W26

Grade

API for performance-based payroll

GrazeMate logo
W26

GrazeMate

Robot Cowboys that Herd Cattle with AI Drones

Haladir logo
W26

Haladir

Operational Superintelligence for Global Logistics

Hex Security logo
W26

Hex Security

Agentic Offensive Security at Scale

Hlabs logo
W26

Hlabs

US-Made Parts for Robots

Human Archive logo
W26

Human Archive

Multimodal data provider for robotics and world modeling

IncidentFox logo
W26

IncidentFox

AI SRE agent that triages, coordinates, and fixes production incidents

Instinct logo
W26

Instinct

Trade your instinct

InventoryQuant logo
W26

InventoryQuant

We automate the inventory process in insurance

Inviscid AI logo
W26

Inviscid AI

Real-time Physics Simulations for Industrial Facilities & Data Centers

Jinba logo
W26

Jinba

Automate enterprise workflows through chat

Kita logo
W26

Kita

Automate credit review for lenders in emerging markets

Klaus AI logo
W26

Klaus AI

Fast and Safe OpenClaw on the cloud

Kyten Technologies logo
W26

Kyten Technologies

Custom Aerospace-Grade Battery Packs

Lance logo
W26

Lance

AI Agents That Run Hotel Operations.

Laurence logo
W26

Laurence

Hedge fund for ads

LegalOS logo
W26

LegalOS

The AI-Native Immigration Law Firm

Lexius logo
W26

Lexius

AI for Corporate Security Cameras

Lucent logo
W26

Lucent

AI that automatically improves products from user behavior

Luel logo
W26

Luel

Turning everyday words and actions into usable training data.

Mango Medical logo
W26

Mango Medical

Foundation models for planning orthopedic surgery

Mantis logo
W26

Mantis

Digital Twins of humans

Martini logo
W26

Martini

AI Video Production for Professionals

Maven logo
W26

Maven

Payments Infrastructure for Voice Agents

Maywood logo
W26

Maywood

The first finance-compliant proactive AI that runs 24/7

Mendral logo
W26

Mendral

AI DevOps Engineer

Menza logo
W26

Menza

The AI data analyst for consumer brands

enterprise applications · United Kingdom

Milliray logo
W26

Milliray

Technology to detect and track small drones

MochaCare logo
W26

MochaCare

Agentic Management Service for Care Organizations

Moda logo
W26

Moda

The monitoring layer your AI agents need.

Moritz logo
W26

Moritz

Global AI-native law firm handling legal work with same-day turnaround

MouseCat logo
W26

MouseCat

AI-powered fraud investigations

Ndea logo
W26

Ndea

Building AGI that can innovate.

OctaPulse logo
W26

OctaPulse

CV and robotics to automate quality inspection in fish farms

One Robot logo
W26

One Robot

World models for robot evals and training.

Opalite Health logo
W26

Opalite Health

Helping Healthcare Providers Speak Any Language

OpenSpec logo
W26

OpenSpec

Plan mode for complex features

Origami Robotics logo
W26

Origami Robotics

Manipulate Anything Robot

Origin logo
W26

Origin

AI and Data for Cancer Therapeutics

Orthogonal logo
W26

Orthogonal

Agentic Payments for APIs

Overdrive Health logo
W26

Overdrive Health

AI-Native Medical Billing Services

Overshoot logo
W26

Overshoot

AI Infra for real-time vision applications

Oximy logo
W26

Oximy

See and control all AI activity across your enterprise

Oxus logo
W26

Oxus

AI-powered automation for internal audit workflows

Palus Finance logo
W26

Palus Finance

40% higher yields on company cash, in under 5 minutes.

Panta logo
W26

Panta

AI Native Commercial Insurance Brokerage

Patientdesk.ai logo
W26

Patientdesk.ai

AI front & back office agent for dental practices

Pax Historia logo
W26

Pax Historia

The first AI-powered grand strategy platform

Payna logo
W26

Payna

AI Licensing Agent for Regulated Industries

Perfectly logo
W26

Perfectly

The AI-native Recruiting OS

Piris Labs logo
W26

Piris Labs

Inference at Light Speed

Pocket logo
W26

Pocket

Take Notes in the Real World

Pollen logo
W26

Pollen

AI agents that automate customer success

Pollinate logo
W26

Pollinate

AI Agents for the supply chain.

Polymath logo
W26

Polymath

Simulation environments to train & evaluate long-horizon AI agents

Polymorph logo
W26

Polymorph

Personalization infra that improves retention, LTV, and CAC

Prana logo
W26

Prana

An AI primary care doctor in your pocket

Protent logo
W26

Protent

Real time intelligence for law enforcement & security teams.

Proximitty logo
W26

Proximitty

AI operating system for commercial loans

Q2Q logo
W26

Q2Q

We help private equity teams find acquisition targets faster

REV1 logo
W26

REV1

Claude Code for Mechanical Engineers

RamAIn logo
W26

RamAIn

Automate any UI task with natural language

Reframe logo
W26

Reframe

AI-native, hardware procurement marketplace

healthcare · United States

Remix logo
W26

Remix

Social media content auto-generated with your existing data

Remy AI logo
W26

Remy AI

Documenting human dexterity

Ressl AI logo
W26

Ressl AI

AI Workers for Field Services

Revion logo
W26

Revion

Intelligence for Automotive Operations

Rhizome AI logo
W26

Rhizome AI

Agent Platform for Life Sciences

Ritivel logo
W26

Ritivel

AI-native platform for Life-Sciences Documentation

Robby logo
W26

Robby

AI agents that grow revenue for home services businesses

RoboDock logo
W26

RoboDock

Robots that run autonomous depots for autonomous fleets.

Rubric AI logo
W26

Rubric AI

Reasoning and verification infra for AI

Ruma Care logo
W26

Ruma Care

The operations stack for biologic infusion clinics

RunAnywhere logo
W26

RunAnywhere

The default way of running on-device AI at Scale

Salus logo
W26

Salus

Guardrails to validate your agent's actions before they execute

Samora AI logo
W26

Samora AI

Multilingual voice agents that outperform humans

Scheduling Wizard logo
W26

Scheduling Wizard

Logistics infrastructure to modernize healthcare operations

Seeing Systems logo
W26

Seeing Systems

Modular AI-Commanded Drones for Defence

Sentrial logo
W26

Sentrial

Datadog for Agent Reliability

Sequence Markets logo
W26

Sequence Markets

Low-latency execution across crypto, prediction, and tokenized assets

Servo7 logo
W26

Servo7

Robots that 10x manual industry work

Shofo logo
W26

Shofo

The World's Largest Video Library

Signals logo
W26

Signals

Proactive AI customer support that engages high-value users

Sila logo
W26

Sila

AI Work Messaging & Collaboration Platform

Skillsync logo
W26

Skillsync

Hire engineers based on what they’ve shipped

Sonarly logo
W26

Sonarly

Makes software self-healing

Sparkles logo
W26

Sparkles

Make everyone on your team an engineer

Sponge logo
W26

Sponge

Financial infrastructure for the agent economy

SpotPay logo
W26

SpotPay

Stablecoin Global Bank Account

Squid logo
W26

Squid

AI agents for power grid planning 🦑

Stilta logo
W26

Stilta

Agentic AI for intellectual property

Strand AI logo
W26

Strand AI

Multimodal foundation models to predict uncollected patient biology

Supafax logo
W26

Supafax

AI assistant for your email and calendar

Synthetic Sciences logo
W26

Synthetic Sciences

Claude Code for Scientific Research

Syntropy logo
W26

Syntropy

The agentic coding app for complex tasks.

Talking Computers logo
W26

Talking Computers

AI for AI Infrastructure

Tepali logo
W26

Tepali

AI-native operating system for aesthetics & wellness

Terminal Use logo
W26

Terminal Use

Vercel for background agents

Terranox AI logo
W26

Terranox AI

The first AI-powered uranium discovery company

The Token Company logo
W26

The Token Company

Compression middleware that improves LLM outputs

Traverse logo
W26

Traverse

Research lab solving non-verifiable work

Travo logo
W26

Travo

The data infrastructure for real estate

Unifold logo
W26

Unifold

Multi-chain deposit and payment infrastructure

Unisson logo
W26

Unisson

AI agents that automate B2B software implementation

VOYGR logo
W26

VOYGR

Real-world place intelligence for AI apps and agents

Valence logo
W26

Valence

Unified prediction markets trading platform

Valgo logo
W26

Valgo

Insurance risk layer for physical AI

Vector Legal logo
W26

Vector Legal

Full service ai law firm & software solution, for startups

Vela logo
W26

Vela

AI Agents For Complex Scheduling Coordination

Velum Labs logo
W26

Velum Labs

The OS for data quality across any stack

Ventura logo
W26

Ventura

AI Workforce for Distributors and Manufacturers

Verdex logo
W26

Verdex

AI Verification for Insurance

Visibl Semiconductors logo
W26

Visibl Semiconductors

A faster, lower cost path to custom silicon

Voltair logo
W26

Voltair

Autonomous Drones for Earth Observation

Voxel Energy logo
W26

Voxel Energy

Energy independent data centers with solar and repurposed batteries.

Wayco logo
W26

Wayco

AI operator for medlegal cases

Wideframe logo
W26

Wideframe

AI coworker for video editors to ship more video faster

Zatanna logo
W26

Zatanna

Turning all software into agent-first APIs

ZeroSettle logo
W26

ZeroSettle

Drop-in Direct Billing SDK for In-App Purchases

Zymbly logo
W26

Zymbly

Automates admin for aircraft mechanics

o11 logo
W26

o11

The AI Agent Inside Every Enterprise App

shortkit logo
W26

shortkit

Media infra for consumer apps

sitefire logo
W26

sitefire

Marketing suite for the agentic web

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