Y Combinator Winter 2025 (W25) Companies

Inversion Semiconductor develops next-generation semiconductor lithography equipment based on miniaturized particle accelerators that increase transistor density and improve chip manufacturing precision. The platform enables semiconductor fabricators to scale transistor production toward physical limits while improving throughput and uniformity in advanced chip production.

7 investors

Invo is an AI agent platform that automates purchase order processing, RFQ review, and accounts receivable management for businesses by extracting and validating data from emails, PDFs, and portals.

1 investor

Karoo is a financial services company operating in Canada that aims to provide fairer and more customer-focused financial products and services.

3 investors

Karsa offers business and personal banking services for companies across 50+ countries, providing multi-currency accounts, international payments, and corporate cards with support for ACH, wire transfers, SWIFT, SEPA, and stablecoin transactions.

2 investors

LeapingAI builds AI voice and text agents that automate inbound and outbound calls for enterprises, handling customer support, appointment setting, and lead qualification. The platform integrates with CRMs and business tools to manage call center operations at scale.

3 investors

Lopus provides analytics and data integration dashboards that connect to 500+ data sources and existing data warehouses, enabling businesses to set up analytics quickly and identify revenue opportunities across their customer data.

1 investor

Lucid develops video models that simulate interactive three-dimensional environments by using neural networks in place of traditional game engines, enabling real-time control and visual generation on consumer hardware.

1 investor

Lucidic builds a platform for optimizing AI agent behavior through automated simulations and parameter tuning. The platform helps teams improve agent reliability, accuracy, and performance across customer-facing applications by systematically varying design choices like prompts, tools, policies, and guardrails.

1 investor

Macadamia Labs provides AI agents that automate engineering and back-office processes for engineering firms, including tasks like AutoCAD design generation, P&ID verification, and technical documentation review.

1 investor

AI assistant that grades roofing sales rep performance against sales processes and provides coaching for residential roofing companies. It uses outcome-based pricing.

2 investors

Maritime Fusion designs and builds zero-emission fusion reactors for deployment in maritime transport and remote energy installations. The company aims to use these off-grid applications as a pathway to develop cost-competitive grid-scale fusion reactors.

4 investors

Mastra is an open-source TypeScript framework for building AI agents. The platform serves developers and teams building agent-based applications.

6 investors

Mecha Health develops foundation models for radiology that generate complete diagnostic reports from medical images using vision-language AI systems. The company aims to amplify radiologists' expertise to enable faster clinical workflows and better patient outcomes at scale.

3 investors

Mentra builds smart glasses hardware, an open-source operating system (MentraOS), and developer tools for deploying applications on smart glasses. The platform serves developers, hardware manufacturers, and end-users seeking accessible and privacy-respecting wearable AI interfaces.

5 investors

Mercura builds software to improve productivity and operations at companies in construction and manufacturing. The company serves enterprises in traditional industries that form the backbone of the economy.

2 investors

Mesh automates accruals accounting for finance teams by extracting transaction data from accounts payable systems and communication platforms to generate audit-ready entries, reducing manual month-end close work.

1 investor

Misprint operates a marketplace for buying, selling, and trading graded Pokémon cards, using machine learning algorithms to provide real-time pricing analytics and transparent bid/ask matching for collectors and investors.

1 investor

Miyagi provides an AI-powered test prep platform for standardized exams like the SAT, offering personalized study paths, diagnostic assessments, and adaptive tutoring. The platform targets high school students preparing for college entrance exams.

1 investor

Mosaic provides a platform for creating autonomous agents that perform video editing tasks, reducing work that typically takes hours down to seconds.

2 investors

Mundo AI creates a multilingual dataset library to address the scarcity of high-quality training data in languages other than English for AI model development.

3 investors

Nitrode builds AI evaluation, data generation, and post-training infrastructure for game development. The company specializes in measuring where AI models fail in game creation tasks, generating training data for improvement, and creating environments where models can learn through real interaction.

2 investors

Oki Home is a local AI device that stores photos, files, and personal data on-device while providing conversational AI capabilities for tasks like meeting scheduling and information retrieval. The product targets individuals seeking privacy-preserving personal AI assistance with local processing and no data leaving the device.

1 investor

1 investor

Onlook builds developer and design tools that bridge the gap between creative teams and implementation, using AI to enhance the creative process.

5 investors