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Fastest growing YC companies

The 100 Y Combinator companies whose team grew the most in the last 6 months (active companies with 10+ people).

Updated weekly, last on November 9, 2026. Roster from Y Combinator's public directory.

Showing 100 of 100 companies on this list
#CompanyBatchTeam6 mo12 moOpen rolesTotal raisedLast round
1
Physical AI data lab
W2695+579% 3$8.7MSeed$8.2M, May 2026
2
Voice AI for Enterprises
S2550+355%+900%YC$4MGrant$3.5M, Jul 2026
3
Industrial data layer for physical RSI
X2556+331% 0$7.6MSeed$6M, Jun 2026
4
The data layer for perceptual intelligence
W2544+300%+450%2$24MSeries A$20M, Aug 2026
5
AI-native operating system for home service businesses
W22124+254%+675%10$23.7MUndisclosed round$23.7M, Feb 2026
6
Scale marketing campaigns across hundreds of personas
X2620+233%+300%0$500KYC investment$500K, Jun 2026
7
Elite AI law firm for high growth companies
W2649+227% 2$11.5MSeed$11.5M, Feb 2026
8
AI pentesting, that works!
W2616+220% 7$500KYC investment$500K, Mar 2026
9
Full-Stack AI Accounting
W2616+220% YC$500KYC investment$500K, Feb 2026
10
Supplying America's Industrial Base
S2535+218%+600%YC$16.8MSeed$11.5M, Jun 2026
11
The open source AI coding agent
W2121+200% 0
12
AI that makes AI fast
S2518+200% 2$44.8MSeries A$40M, Sep 2026
13
Real-world training data for frontier AI labs and robotics.
X2653+194%+152%YC
14
We Handle AI. You Direct Films.
F2520+186% 1$6.5MSeed$6M, May 2026
15
The Waymo of Personalized demos
F2516+167% YCSeedDec 2025
16
Metal manufacturing, faster, cheaper, and more versatile.
S2616+167% 0
17
Agentic AI for Society Builders
F2529+164%+480%YC$8.5MSeed$8M, Jan 2026
18
AI healthcare concierge for employees
F2513+160% YC$500KYC investment$500K, Dec 2025
19
Agents that own the work
X2613+160% YC$45.8MUndisclosed round$12.8M, Oct 2026
20
Autonomous Company Infrastructure
X2515+150%+200%3$28.5MSeries A$28.5M, Aug 2026
21
Patreon for AI Originals
X2622+144% 0$500KYC investment$500K, Jun 2026
22
Real World Environments and Data for AI
F2517+143%+143%0$500KYC investment$500K, Dec 2025
23
Renewable infrastructure deployment at scale.
S2412+140% 0$4.4MSeed$3.9M, Apr 2026
24
Global AI-native law firm handling legal work with same-day turnaround
W2622+120% 1$9MSeed$9M, May 2026
25
Counter Drone Systems. $1.6m sales. We delivered for the DoW.
X2622+120%+214%10$500KYC investment$500K, Jun 2026
26
Automating claims processing workflows for health insurance payers.
F2511+120% 0SeedJan 2026
27
Compression middleware that improves LLM outputs
W2611+120% 0$500KYC investment$500K, Mar 2026
28
The deterministic layer for frontier intelligence
F2413+117% YC$7.2MSeed$7.2M, Feb 2025
29
Frontier Video Agents
W2513+117%+117%YC$500KYC investment$500K, Mar 2025
30
Intelligence Infrastructure on People and Entities
X2513+117%+160%YC$500KYC investment$500K, Apr 2025
31
We make the most compact nuclear reactors
X2613+117% 0$32.1MUndisclosed round$620K, Sep 2026
32
Open data platform for traceable, multimodal AI
S2228+115%+100%0SeedOct 2022
33
Large-scale real-world robot & human data for embodied AI
F2519+111%+138%0$6MSeed$6M, Dec 2025
34
The GPU Cloud Marketplace
S2321+110%+200%YCSeedJan 2025
35
Secure frontier AI for government & adjacent knowledge work
S2521+110%+250%YC$10.9MSeed$10.9M, Oct 2025
36
The relationship intelligence platform for enterprise revenue
W2429+107%+142%3$19.5MSeries A$15M, Jul 2026
37
AI-native medical record retrieval
S2463+103%+385%3$500KYC investment$500K, Jan 2026
38
AI Phone Agents for Healthcare Operations
S2370+100%+400%4$35MSeries A$30M, Jun 2026
39
AI Time Platform for Law Firms
W2442+100%+320%9$19.6MSeries A$16M, Mar 2026
40
Practical, general-purpose robots for repetitive industrial tasks
S2438+100%+192%YC$62MSeries A$50M, Oct 2026
41
Call every LLM API like it's OpenAI [100+ LLMs]
W2326+100%+333%1
42
AI Compliance Platform for Healthcare Organizations
S2324+100%+300%1$11MSeries A$11M, Oct 2026
43
Automating collection and boosting cashflow for B2B companies
S2212+100%+100%0$2MPre-seed$2M, Sep 2022
44
AI engineering capacity. Made simple. ⚡️
S2110+100% YCPre-seedAug 2021
45
The unified context layer for enterprise data
W2410+100%+67%YC$2.3MYC investment$500K, Mar 2024
46
A personal EA in your iMessage
X2510+100%+43%1$2MSeed$2M, Jun 2025
47
Physical businesses that run themselves
F2510+100% YC$500KYC investment$500K, Dec 2025
48
World's largest crowdsourced benchmark for AI-generated design
S2510+100% 0$500KYC investment$500K, Sep 2025
49
Optimizing fleet planning with data driven algorithms
S2510+100% YC$500KYC investment$500K, Sep 2025
50
Robots with soul
F2510+100% YC$1.2MSeed$653K, Feb 2026
51
AI-native ATS/CRM for recruiting firms
W2547+96%+327%2$24.2MSeries A$21M, Sep 2026
52
We Bring Customers to Your Dealership
S2535+94%+289%15$33.5MSeries A$27M, Oct 2026
53
The AI-Native Turnkey Alternative Investment Platform (TAIP)
S2129+93%+142%YC$18.9MSeries A$15M, Sep 2026
54
Ploy turns your website into your company's growth engine.
X2627+93% 2$27MSeed$27M, Jun 2026
55
Build autonomous AI agents for enterprise systems
X2550+92%+355%4
56
Look inside the model
S2425+92%+257%0$500KYC investment$500K, Jan 2026
57
AI Scheduling for Short Haul Trucks
X2621+91%+91%0$500KYC investment$500K, Jun 2026
58
The AI platform for private markets investors
S2538+90%+81%6$29MSeed$5M, Sep 2026
59
Autonomous surgical robots
S2319+90%+73%5$15.6MSeries A$15M, Aug 2026
60
AI-enabled financial automation and intelligence for CPG Brands
S21121+89%+163%22$75MSeries B$55M, Sep 2026
61
Corgi is building an AI financial infrastructure company
S24402+88%+272%16$439MSeries B$64M, Sep 2026
62
Practice admin run by AI
W2415+88%+150%YC$6MPre-seed$6M, Feb 2024
63
The AI-native financial platform for enterprises
S2226+86%+189%0SeedJan 2024
64
Yarn is the video product for agentic GTM teams.
W2413+86%+160%YC$500KSeed$500K, Jan 2026
65
The Agent-Native Computer
X2513+86%+117%YC
66
creators of folk.com
S2513+86%+117%YC$8.2MSeed$6.2M, Oct 2025
67
Your Personal AI for everyday work. Lives in your texts.
F2513+86% 0$500KYC investment$500K, Dec 2025
68
Invest in Global Equities from India
S2424+85%+167%0$500KYC investment$500K, Sep 2024
69
AI workforce for property management
W2311+83%+120%YC$500KYC investment$500K, Apr 2023
70
AI models that teach robots new skills in hours
S2511+83% YC$500KYC investment$500K, Sep 2025
71
The AI data analyst for biology labs
S2511+83%+83%YC$500KYC investment$500K, Jul 2025
72
AGI for home service
S2511+83% YC$500KYC investment$500K, Sep 2025
73
Your Company Brain
F2511+83%+120%YC$7.1MSeed$7.1M, Dec 2025
74
AI outpatient care workforce
F2511+83% 0SeedDec 2025
75
Intelligence that runs your operations.
S23260+83%+192%36$211MSeries C$150M, Aug 2026
76
Modern health insurance for dual income families
W2442+83%+147%YC$14.5MSeries A$14M, Jul 2026
77
Multilingual voice agents that outperform humans
W2620+82%+122%0$500KYC investment$500K, Apr 2026
78
The agentic operating system for legal work
W24980+81%+321%123$866MSeries D$50M, Apr 2026
79
AI for ASIC Design Verification
S2316+78%+167%0$500KYC investment$500K, Sep 2023
80
robots & software for farms
X2616+78% 0$500KYC investment$500K, May 2026
81
Vertical AI agents running B2B outbound on autopilot, with human SDRs
X25140+77%+724%0$6.2MSeed$6.2M, Sep 2025
82
AI agent for Accounts Receivable
S2444+76%+389%2$21.7MUndisclosed round$17M, Aug 2026
83
AI employees that take on real work, starting with sales
W24342+75%+4,786%2$46.1MSeries A$25M, Apr 2025
84
TurboTax for Medicaid
S2328+75%+65%1$22.3MSeries A$18.3M, Jul 2025
85
Autonomous security testing for web apps, APIs, cloud, and AI systems
X2521+75%+200%YC$17.2MSeries A$13M, Jul 2026
86
Voice AI
S2214+75%+27%0
87
AI-powered risk and compliance for financial institutions
S2314+75% YC$11MNon-equity support$11M, Mar 2026
88
The cheapest way to borrow money
S2326+73%+225%1$500KSeed$500K, Jun 2026
89
America's #1 Sports Trading App
S2298+72%+165%9$99.9MSeries B$75M, Feb 2026
90
AI agent that saves you money on travel
W1948+71%+200%1
91
Take Notes in the Real World
W2624+71%+243%19$11.5MSeed$11M, Jun 2026
92
Accelerate software development with WarpBuild's 10x faster CI infra.
S2112+71%+71%1$1.5MPre-seed$1.5M, Aug 2021
93
Airplanes anyone can fly
S2212+71%+140%YC$4.6MUndisclosed round$4.6M, Oct 2025
94
The AI operating system for commodity operations
W2412+71%+71%YC$500KUndisclosed round$500K, Jan 2026
95
The app platform inside Claude and ChatGPT.
S2512+71% YC$500KYC investment$500K, Jul 2025
96
AI property manager for landlords and estate agents
F2512+71% YC$500KYC investment$500K, Dec 2025
97
The OS for hospital workforce management
W2517+70%+240%YC$500KYC investment$500K, Mar 2025
98
The high-performance file system that connects AI to data
F2417+70%+240%0$18.2MSeries A$11M, Apr 2026
99
AI Recruiting Coordinator for Executive Search
W2617+70% YC$500KYC investment$500K, Mar 2026
100
AI Agents for Recruiting
S22158+70%+187%33$116MSeries B$80M, Mar 2026

How this works

1. The roster

Every launched company in YC's public directory, with its batch, status, industry and location. New companies show up the week YC lists them.

2. The numbers

Each company is matched to Crustdata by its website. Crustdata adds team size and its change over 6 and 12 months, open roles from job postings, reported funding, and founders' past employers.

3. The lists

Hiring the most counts distinct roles posted in the last 60 days. Growth needs 10+ people today, shrinking 20+ a year ago, so tiny teams do not top the lists. Rebuilt every week.

Built with Crustdata. Get your own API key and build your own.

The numbers on this page come from three Crustdata API calls. Crustdata tags 5,000+ companies with Y Combinator as an investor; swap the filter for any investor, industry or headcount range and track your own list, with founders' work emails one call away.

  • Company search for team size, growth and funding
  • Job search with a count by company, for who is hiring and for what
  • A watch that re-runs the search weekly and sends only what changed
# 1. every company with Y Combinator as an investor
curl https://api.crustdata.com/company/search \
  -H "authorization: Bearer $CRUSTDATA_API_KEY" \
  -H "x-api-version: 2025-11-01" \
  -d '{
    "filters": { "field": "funding.investors",
                 "type": "in", "value": ["Y Combinator"] },
    "fields": ["basic_info.name",
      "headcount.total", "headcount.growth_percent",
      "funding.total_investment_usd"],
    "limit": 100
  }'

# 2. open listings per company, last 60 days (limit 0 = counts only)
curl https://api.crustdata.com/job/search \
  -H "authorization: Bearer $CRUSTDATA_API_KEY" \
  -H "x-api-version: 2025-11-01" \
  -d '{
  "filters": { "op": "and", "conditions": [
    { "field": "company.basic_info.company_id",
      "type": "in", "value": [...] },
    { "field": "metadata.date_added",
      "type": "=>", "value": "2026-08-24" } ]},
  "limit": 0,
  "aggregations": [{ "type": "group_by",
    "field": "company.basic_info.company_id", "agg": "count" }]
}'

# 3. the same company filter as a weekly watch: POST /watch/company/search

Questions people ask about YC companies

How many companies has Y Combinator funded?

YC's public directory lists 6,376 launched companies across 50 batches since 2005: 4,406 active, 839 acquired, 23 public and 1,108 listed as inactive.

What is the latest YC batch?

The newest batch with companies in the directory is Fall 2026 (219 companies). YC has also started listing Summer 2027 (1) and Winter 2027 (9). YC runs four batches a year: Winter, Spring, Summer and Fall.

What are the biggest YC companies?

By people listing them as their employer on public profiles (which can include contractors, drivers and hosts): DoorDash (84,144), Instacart (25,483), Stripe (16,694), Rappi (15,009) and Deel (9,642). 23 YC companies are public and 839 were acquired. Sort the table by Largest team to see the rest.

Which YC companies are hiring?

We found job postings in the last 60 days for 719 YC companies, led by Stripe (659 roles), EquipmentShare (262 roles) and Relativity Space (244 roles); another 1,017 say they are hiring on YC's directory. See YC companies hiring the most, or filter by Hiring for (engineering, sales and more). We count distinct role titles, because the same job is often posted on several job boards.

Which YC companies are growing fastest?

Ranked by team growth over the last 6 months, among active companies with 10 or more people: Human Archive (+579%), Freya (+355%) and Linewise (+331%). See the fastest growing YC companies, or open any batch and pick Fastest growing.

How is team size counted?

Team is the number of people who list the company as their current employer on public professional profiles, counted by Crustdata every month. It can differ from a company's own number (contractors, people who have not updated their profile). The 6 and 12 month changes compare that count with the same count back then, and we only show a change when the team had at least 5 people at the start.

Which YC companies failed or shut down?

1,108 companies are listed as inactive in YC's directory, which usually means they shut down or stopped operating. Filter the table by Status, Inactive to see them. YC does not publish why a company became inactive, and some inactive companies were acqui-hired.

How do I get the list of YC companies as a CSV?

Use Export CSV above the table. It downloads whatever you are looking at (a batch, a list, your filters and search) with domain, batch, status, team size and change, open roles, funding, investors and founders with their profile links. It asks for your email once; we never send anything to it.

Where does this data come from?

The list of companies, batches, industries and locations comes from Y Combinator's public directory, via the open yc-oss dataset. Team size and growth, open roles, funding and founders come from the Crustdata API, which tracks 60M+ companies and 1B+ public professional profiles, and job postings. Each company is matched by its website and its name; 945 companies have no Crustdata record yet and show YC's data only. Funding is reported funding (including debt in the total) and can be incomplete.

How often is it updated?

Every week. The last update was on November 9, 2026. Founders are refreshed monthly. New companies appear the week YC adds them to its directory.

Browse YC companies

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