startup ideas · graveyard
Dead startup ideas worth reviving
Of the 10,190 accelerator companies from 2018 onwards that MarkosWeb can check, 1,454 (14%) are dead: Y Combinator marks them inactive, or their website no longer answers. A dead company is not a dead idea. The list below sorts graveyards by how many new companies entered the same cluster in 2025-26 and are still alive - the clearest sign that founders believe the timing has changed.
1,454
dead or vanished since 2018
14%
of checked companies
58
YC shutdowns since 2026-02
15
clusters with a graveyard
How to tell a revivable idea from a dead one
- The blocker flipped. Most of these companies were right about the destination and early on a dependency: model cost, a regulation, a distribution channel, hardware price. Check which one killed the original and whether it has moved since.
- Someone still pays. A real buyer has to be paying for a worse solution today. Run the one-liner through Idea Check to see who is alive in the same space and how alive they are.
- Founders are coming back. The re-entrant count next to each cluster is the number of 2025-26 companies building there now. A graveyard nobody re-enters is a warning; one with hundreds of new entrants is a market that was early, not wrong.
Graveyards founders are re-entering
Per cluster: companies dead since 2018 with a recorded one-liner, the number of live 2025-26 entrants, and the most recent casualties. Names link to their MarkosWeb domain report.
Vertical AI agents63 dead · 413 new entrants since 2025
- Q2Q · Y Combinator W26 · 2026 - We help private equity teams find acquisition targets faster
- Remedy · Y Combinator F25 · 2025 - AI Agents for Pharmacies
- Oblix, Inc · 500 Global · 2025 - Helping pentesters do 10x more security testing with autonomous offensive AI agents
- Caucus · Y Combinator X25 · 2025 - AI CRM for Government
- Galen AI · Y Combinator X25 · 2025 - Personal AI healthcare agent, powered by clinical and wearable data.
- Kanava AI · Y Combinator X25 · 2025 - Your First AI Sales Hire for Wholesale Distributors
Agent infrastructure18 dead · 200 new entrants since 2025
- Sylvian · Y Combinator F25 · 2025 - Specialized AI Agents.
- Nuntius · Y Combinator S25 · 2025 - Making Models Follow Rules.
- Propolis · Y Combinator X25 · 2025 - Hands off QA via intelligent browser agents.
- Doublezero · Y Combinator S24 · 2024 - Platform to build, use, and monetize fully autonomous agents
- Lantern · Y Combinator W24 · 2024 - Postgres vector database extension to build AI applications
- Tesseral · Y Combinator W24 · 2024 - The open source platform for managing identity in business software
Robotics and physical world36 dead · 126 new entrants since 2025
- Kyten Technologies · Y Combinator W26 · 2026 - Custom Aerospace-Grade Battery Packs
- Foundation Industries · Y Combinator X25 · 2025 - We supply hard tech companies with critical components.
- GeoGrid · 500 Global · 2025 - Provider of water infrastructure technology, offering building-wide purification and predictive analytics through proprietary pipeline coating and monitoring solutions.
- K-Scale Labs · Y Combinator W24 · 2024 - Open-source humanoid robots
- Selera Medical · Y Combinator W24 · 2024 - One-time, device-based treatment for heart failure
- Moviation · 500 Global · 2023 - Develper of an air mobility platform intended to provide safety and convenience based on expertise and data. The company's platform uses the inherent value of mobilization by utilizing conventional helicopters and eventually replacing all fleets with eVTOLs, enabling clients to get pleasant and quality mobility experiences.
Healthcare and bio62 dead · 111 new entrants since 2025
- Layers · Y Combinator F25 · 2025 - A 30 min appointment to measure everything in your body
- TwentyTwo · Y Combinator S25 · 2025 - AI infrastructure for biosecurity
- Exin Therapeutics · Y Combinator W25 · 2025 - AI drug discovery platform for neurotherapeutics
- Pontrx · 500 Global 500G GA 35 · 2024 - PontRx enables provider-patient channel communication to save physician time and streamline access to care
- Eris Biotech · Y Combinator W24 · 2024 - Our drugs engage the immune system to fight tumors
- SynsoryBio · Y Combinator W24 · 2024 - "If-then" conditional logic for protein drugs
Fintech114 dead · 95 new entrants since 2025
- Fortu · 500 Global 500G Georgia 4 · 2023 - Provider of digital private banking services intended to design a borderless, private and personal finance remedy. The company provides financing options for high-net-worth individuals and businesses requiring secure, reliable and international financial reach by offering multicurrency payment accounts with easy access to financial services, enabling HNIs and customers to enjoy financial freedom and gain complete control over their finances.
- Taskeer Holdings Limited · 500 Global 500G MENA 5 · 2023 - Provider of financial solutions intended to facilitate traditional monthly group savings. The company's platform enables monthly collections that contribute to facilitating money-saving concepts, taking into consideration any challenges and constraints, enabling consumers to get assurance of quality standards, trusted members and accurate receiving dates.
- Paperplane · Y Combinator W23 · 2023 - Credit risk management platform for builders' merchants
- Pier · Y Combinator W23 · 2023 - Stripe for Credit - Trusted Credit Compliance Partner
- Ruby Card · Y Combinator W23 · 2023 - Neobank for e-commerce businesses
- Ztock · 500 Global · 2022 - Operator of an investment application intended to invest in the capital markets. The company's platform offers to trade stocks and ETFs in the United States and the Philippines and also provides security for the funds and build portfolios, enabling financial institutions' data encryption and empowering the next generation of investors.
Developer tools101 dead · 87 new entrants since 2025
- EverySim · 500 Global · 2025 - Developer of a cloud-native engineering simulation platform designed to enable browser-based design, testing, and optimization of UAV airframes. The company integrates CFD, FEA, and AI-driven optimization into a single SaaS workflow that replaces fragmented toolchains and costly hardware, enabling both expert and non-expert engineers to run high-fidelity simulations easily and affordably.
- Rovr · Y Combinator F25 · 2025 - AI FDE Engine that runs your engineering workflows
- Sublingual · Y Combinator W25 · 2025 - Daily productivity tracker
- Gait · Y Combinator F24 · 2024 - Building Dev Infra for AI Software Engineers
- Invaria · Y Combinator S24 · 2024 - The next generation logging and observability platform
- MagiCode · Y Combinator S24 · 2024 - A Reliable AI Frontend Engineer
B2B SaaS131 dead · 83 new entrants since 2025
- Smartbase · Y Combinator X26 · 2026 - AI-native ERP for manufacturers
- Anchorhead · Y Combinator W26 · 2026 - Fractional buyer for hardware companies in critical industries
- Gander · Y Combinator F24 · 2024 - Automation System for Global Aviation
- Matcha · Y Combinator F24 · 2024 - The best way to hire clinical talent.
- Instanture · 500 Global · 2024 - Our suite of AI SAAS help brand & distributor to manage their order & pay operation across multiple sales channels
- Flyflow · Y Combinator S24 · 2024 - The easiest way to find high-quality sales leads
Consumer176 dead · 73 new entrants since 2025
- Tee Time Tommy · Y Combinator W25 · 2025 - Book and manage all of your golf tee times in one place.
- BeeBettor · Y Combinator S24 · 2024 - Robinhood for sports prediction markets
- ReelProp AI · 500 Global 500G GA 35 · 2024 - Revolutionize Interior Design with AI-Powered 3D Modelling
- Browser Buddy · Y Combinator W24 · 2024 - A recommendation system for great Internet writing
- Lumona · Y Combinator W24 · 2024 - AI-enabled search engine featuring insights from social media.
- OddsView · Y Combinator W24 · 2024 - The Bloomberg Terminal of Sports Betting
7 more clusters
AI infra and compute13 dead · 66 new entrants since 2025
- deepsilicon · Y Combinator S24 · 2024 - Software and hardware to run neural networks faster and cheaper
- Blyss · Y Combinator W23 · 2023 - End-to-end encrypted AI.
- PlayAI · Y Combinator W23 · 2023 - Our mission is to make Voice AI accessible and useful to all.
- PoplarML · Y Combinator W23 · 2023 - Deploy Machine Learning Models with One Command
Data for AI30 dead · 55 new entrants since 2025
- Praxis Robotics · Y Combinator S26 · 2026 - Turns every company into a data vendor
- Percival · Y Combinator X25 · 2025 - Accelerating data analysis for research
- Sepal AI · Y Combinator S24 · 2024 - Data Development for Advanced AI
- Glimmer · Y Combinator W24 · 2024 - AI search for massive PDFs
Security and compliance23 dead · 54 new entrants since 2025
- Cerberus · 500 Global 500G Eurasia 10 · 2026 - Cerberus is the world's first mathematically safe AI ethical hacker — the "Cursor for hacking" that makes security teams 10x more productive with AI that's provably guaranteed never to cause harm.
- Aedilic · Y Combinator W24 · 2024 - Open-Source AI-generated image/deepfake detection
- Alterya · Y Combinator S22 · 2022 - Protecting Humans from Scams
- Notebook Labs · Y Combinator S22 · 2022 - Decentralized, anonymous, and accountable identity on Web3.
Horizontal AI assistants29 dead · 47 new entrants since 2025
- BaseFrame · Y Combinator W26 · 2026 - Detect what AI can automate for your team
- supercontrast · Y Combinator F24 · 2024 - AI Co-Pilot for Design
- Pre · Y Combinator S24 · 2024 - The AI accountability agent for startup founders
- Patchwork · Y Combinator W24 · 2024 - Your team’s AI powered communication tool
Defense and space3 dead · 46 new entrants since 2025
- Exosonic, Inc. · Y Combinator W20 · 2020 - Developing supersonic UAVs as a pathway to quiet supersonic flight
- Lumineye · Y Combinator S19 · 2019 - X-ray Vision for First Responders
- SpaceRyde · Y Combinator W19 · 2019 - The Rocket Network: Sustainable & On-Demand Delivery Anywhere in Space
Climate and energy26 dead · 33 new entrants since 2025
- Prefer · 500 Global · 2023 - Producer of bean-free coffee intended to provide a product that mimics the coffee bean. The company produces coffee without coffee beans by fermenting surplus food, enabling customers to obtain environmentally sustainable and affordable products.
- GreenTally · Y Combinator S23 · 2023 - Affordable carbon tracking solution for all businesses
- Line.Build · Y Combinator S23 · 2023 - Incentives and financing for energy efficiency upgrades
- Orbio Earth · Y Combinator S23 · 2023 - Tracking methane emissions with satellites
Commerce and marketplaces86 dead · 31 new entrants since 2025
- Dome · Y Combinator F25 · 2025 - A unified API for prediction markets, like Kalshi and Polymarket
- KokkanLogis · 500 Global · 2024 - Operator of Primo, an AI-powered freight transportation brokerage platform that seamlessly connects carriers and shippers while offering additional value-added services like electronic billing and freight control.
- Baycon · 500 Global · 2024 - Operator of a B2C and B2B eSIM platform called 'eSIM Easy" with an emphasis on elevating roaming services for inbound and outbound travelers globally.
- DGI Apparel · Y Combinator W24 · 2024 - Expedia for ordering blank apparel
Shut down in the last six months
YC companies that were active in the 2026-02 snapshot and are marked inactive today (58). The freshest graveyard: the reason each one closed is still findable, and the buyers are still out there. Full trajectory report.
- Kyten Technologies · W26 · Robotics and physical world - Custom Aerospace-Grade Battery Packs
- Dome · F25 · Commerce and marketplaces - A unified API for prediction markets, like Kalshi and Polymarket
- Rovr · F25 · Developer tools - AI FDE Engine that runs your engineering workflows
- Percival · X25 · Data for AI - Accelerating data analysis for research
- Altrina · W25 · Vertical AI agents - The SOP Automation Platform
- Baseline AI · S24 · Vertical AI agents - AI document creation and data management for clinical trials
- Lilac Labs · S24 · Vertical AI agents - We automate the person taking orders at drive-thrus with a voice AI
- Pre · S24 · Horizontal AI assistants - The AI accountability agent for startup founders
- Aedilic · W24 · Security and compliance - Open-Source AI-generated image/deepfake detection
- Glimmer · W24 · Data for AI - AI search for massive PDFs
- K-Scale Labs · W24 · Robotics and physical world - Open-source humanoid robots
- Tesseral · W24 · Agent infrastructure - The open source platform for managing identity in business software
- Thorntale · W24 · Horizontal AI assistants - The world's best presentation editor, powered by AI.
- Atla · S23 · Agent infrastructure - The improvement engine for AI agents
- Leafpress · S23 · Climate and energy - AI Energy Management
- Synch · S23 · B2B SaaS - Supercharging Sales
- Fetchr · W23 · Consumer - The Personal Shopper in Your Pocket
- Gluetrail · W23 · Developer tools - Create step by step articles with screenshots and videos 10x faster
- Homeflow · W23 · B2B SaaS - Simplifying insurance for large real estate investors
- Peeba · W23 · Commerce and marketplaces - Risk-free wholesale for retailers across Southeast Asia
- rift · W23 · B2B SaaS - B2B lead routing made simple
- Turntable · W23 · Developer tools - AI-native operating system for analytics teams
- Almond · S22 · Healthcare and bio - We make it easy to get great ObGyn care in-person and over telehealth
- Alima · W22 · Commerce and marketplaces - Fresh procurement made easy
- Livedocs · W22 · B2B SaaS - A New Kind of Notebook for Data Storytelling
- ngrow.ai · W22 · B2B SaaS - Low-code SaaS for marketing in push notifications
- PeakPath · W22 · B2B SaaS - Smartwatch powered coaching to improve teams sustainable performance
- Ploomber · W22 · AI infra and compute - Heroku for AI
- Seis · W22 · Fintech - Banking 100% in Spanish for the 44 million US Spanish speakers
- Uberduck · W22 · Horizontal AI assistants - Fast, professional content creation with AI audio, image, and video.
- Heimdal · S21 · Climate and energy - Affordable and verified direct air carbon capture and storage
- Mine · S21 · Consumer - The AI personal finance company.
- Nino Foods · S21 · Consumer - Building India's fast food empire
- OneStopKitchen · S21 · Vertical AI agents - AI-Driven Tech & Space Optimization to Scale Restaurants
- outloud.ai · S21 · Vertical AI agents - Building Gong.io for offline retail.
- Patterns · S21 · Vertical AI agents - Next-Gen Financial Analysis and Reporting with AI Agents
- PAYZE · S21 · Fintech - Stripe for former Soviet Union countries
- PropReturns · S21 · Commerce and marketplaces - End-to-end commercial real estate transaction platform
- Verde · S21 · Fintech - Digital lending platform for Brazilian farmers
- AXAR AI · W21 · Developer tools - How great teams ship with AI
- ControlHub · W21 · Commerce and marketplaces - Purchasing Software | Procure-to-Pay SaaS
- Faction · W21 · Robotics and physical world - Driverless electric vehicles at a fraction of the cost of a car.
- Forcyte Biotechnologies · W21 · Healthcare and bio - Discover drugs that control how much cells "squeeze" to treat disease
- Lovd · W21 · Consumer - It's not used, it's Lovd.
- MindPortal · W21 · AI infra and compute - Thought-to-Language AI Models
- Payflow · S20 · Vertical AI agents - AI FP&A Agent for insights, reports, planning and forecasting.
- Shuttle · S20 · Developer tools - Build Backends. Fast.
- Breathe Well-being · W20 · Healthcare and bio - A digital well-being program to help people prevent or manage chronic…
- Peg (formerly Paymobil) · W20 · Fintech - The super simple stablecoin wallet with free transactions
- AudioFocus · S19 · Healthcare and bio - Hearing aids that work in noisy places, like restaurants, using ML.
- PlayAbly · S19 · B2B SaaS - We build games to help brands engage, convert, and retain customers
- Bensen · W19 · Commerce and marketplaces - Online and phone ordering for restaurant takeout and delivery
- Endpoint Health · W19 · Healthcare and bio - Precision-first therapies
- Parker · W19 · Fintech - Parker is a digital bank.
- Federacy · S18 · Security and compliance - Penetration testing and bug bounty platform.
- Torch · W18 · B2B SaaS
- Scope AR · S15 · B2B SaaS - Scope AR is the leading provider of User Guided Augmented Reality…
- Billforward · S14 · Fintech - Subscription billing, rate plan management and analytics as a…
More startup ideas by angle
- AI startup ideas →Where AI-native companies are actually being built
- Trending startup ideas in 2026 →Rising clusters, new vocabulary, agent share
- Stealth startups →How many accelerator startups are really in stealth
Validate any of them: Idea Check shows who already builds it; Idea Lab writes concepts from a cluster's data; Chat matches ideas to what you can build.