Founders Directory LogoFounders Directory

Discover the next generation of startups.

A curated directory of high-growth companies backed by the world's most prestigious venture capital firms.

858Companies

VC Backer

All VCsYCombinator

Industry

All IndustriesB2BMarketplaceTravelFintechConsumerHealthcareEducationIndustrialsReal Estate and ConstructionGovernmentUnspecified

Employees

Any Size1-1011-5051-200201-500501+

Stage

Any StagePre-SeedSeedSeries ASeries BSeries C+

Raised

Any Amount< $1M$1M - $5M$5M - $20M$20M+
/
SortA-Z
Buxfer logo

Buxfer

YCombinator

Buxfer helps you make better spending decisions by making it easy to…

Buxfer is an innovative startup in the tech space.

San Francisco
Y Combinator LogoWinter 2007
Active
Fintech
San Francisco
Byteport logo

Byteport

YCombinator

Global upload acceleration for 1GB-100TB files.

Founded in 2025, Byteport is a technology company that builds mission-critical network infrastructure for robotics, satellite, AI, and enterprise applications all over the world. Businesses of every size—from new startups to public companies—use our software to accelerate file transfer online.

San FranciscoY Combinator LogoWinter 2026ActiveSan Francisco
Cajal logo

Cajal

YCombinator

Scaling formal verification to accelerate scientific discovery

Cajal (YC W26) is massively scaling formal verification to accelerate scientific discovery. We deploy superhuman AI mathematicians to high-impact applied domains, starting with quantum computing and finance. We do this with Lean - a framework that allows us to formally verify any mathematical statement, grounding AI in truth and validating the tools discovered by our systems.

San FranciscoY Combinator LogoWinter 2026ActiveSan Francisco
Callab AI logo

Callab AI

YCombinator

AI voice agents for on-prem telephony stack.

58% of the $400B call center industry runs on on-prem phone systems, and until now bringing AI voice automation to them meant ripping out their entire infrastructure first. That's the largest unserved segment in the market. Callab AI connects directly to legacy PBX systems like Avaya, Cisco UCM, and Mitel, and automates up to 70% of call volume with zero migration needed. We plug into these environments without requiring a rip-and-replace. We serve clients across three continents, including brands like Dunkin Donuts.

San FranciscoY Combinator LogoSpring 2026ActiveSan Francisco
Cambly logo

Cambly

YCombinator

On-demand access to English tutors over video chat.

The Cambly app gives English learners instant 1-on-1 access to friendly native speakers over video chat 24/7. Students get an affordable and convenient way to practice their English and gain confidence. Tutors get to make money helping people from around the world practice English.

San FranciscoY Combinator LogoWinter 2014ActiveEducationSan Francisco
Caper logo

Caper

YCombinator

Plug-and-play cashier-less retail powered by computer vision and AI

Caper focuses on compacting Amazon-Go's technology (image recognition, sensor fusion and artificial intelligence) into a smart shopping cart, allowing each shopper to throw her groceries into the cart and self-checkout without cashiers. The technology is looking to fundamentally transform physical retail and rapidly scale into existing grocery stores.

San Francisco, CAY Combinator LogoWinter 2016AcquiredArtificial IntelligenceCashierless CheckoutComputer VisionRetail Tech
Captain logo

Captain

YCombinator

Give AI agents accurate knowledge search that scales

Captain delivers the most accurate file search engine built for AI agents. We’ll index data from the sources folks already use like S3, SharePoint, and Google Drive, and easily scale multimodal, petabyte-level content search. We’re the Snowflake for Unstructured Data. Captain tops the Open-RAG-Benchmark with over 20% higher accuracy than standard RAG pipelines. We achieve this through robust data processing techniques like embedding normalization across modalities, ensuring that representations cluster by semantic content rather than data type.

San FranciscoY Combinator LogoWinter 2026ActiveB2BAPIData EngineeringInfrastructureSan Francisco
Cardboard logo

Cardboard

YCombinator

Agentic video editor

Cardboard is an agentic video editor for growth/marketing teams and serious creators who need to ship videos consistently. Instead of agencies, long timelines, and infinite review cycles, teams give cardboard a footage + a goal (“3 variants”, “30s hook”, “testimonials”) to get a strong first cut in minutes on which they can iterate quickly. Multimodal LLMs can finally reason over footage, and WebGPU/WebCodecs make a real NLE possible in the browser. For the first time, an “AI director” inside a professional editor can be a reality. We have to build two hard things at once: a high-performance editor in the browser and an agentic editor that is reliable for production use cases. Most startups do one; incumbents can’t rebuild their stack without breaking everything. Saksham and Ishan met in school and have known each other since 15 years. Saksham was Co-founder/CTO of Iterate AI (backed by EF) and posts content on social media; Ishan has spent ~5yr building memory-heavy, performance-critical browser apps at HackerRank (S11) and deeply understands browsers. He has built Hotspoter (5M+ downloads) when he was 14. Together, we’re unusually suited to build the editor core others avoid. Video is becoming the default distribution channel, and the team that iterates fastest compounds attention. Cardboard becomes the default workspace for video production, the way Canva/Figma became the workspace for design - because it’s collaborative, fast, and does the tedious parts for you.

San FranciscoY Combinator LogoWinter 2026ActiveSan Francisco
Cardinal logo

Cardinal

YCombinator

AI Platform for Precision Outbound

Hey YC! We're Devi and Jianna - the founders of Cardinal. TL;DR: Cardinal is the AI platform for precision outbound. We run outbound for 40+ YC companies, like Mintlify, Greptile, and Luminai. The Problem “Spray and Pray” outbound is dead. The best teams at outbound do it with extreme precision. Finding things in common with your customers, staying in touch with them through their content, mapping inbound from signups and ads, tracking website visitors, monitoring various signals, etc. This sounds great in theory, but in reality involves stringing together 10+ tools and hiring a GTM engineer. That’s where Cardinal comes in. Cardinal is an AI platform for precision outbound. Our agents can create workflows that normally require the work of fulltime GTM engineers. If you're a founder or sales leader looking to bring AI into your sales org, would love to chat!

San FranciscoY Combinator LogoWinter 2026ActiveSan Francisco
Care GP logo

Care GP

YCombinator

AI agents to run primary healthcare operations

Care GP is building AI agents to run operations for primary healthcare clinics

Sydney, AustraliaY Combinator LogoSummer 2026ActiveSaaSHealthcareAI
PreviousPage 12 of 86Next