Stilta raises $10.5M seed

Stilta’s $10.5 million seed round is a bet that patent litigation is becoming a software category, not just a legal service. The Stockholm-based startup said on May 19 that Andreessen Horowitz led the financing, with Y Combinator and a group of operators from AI and legal-tech companies joining the round. (law.com) The company is not selling a general-purpose legal chatbot. Stilta is building software for a narrow, expensive part of intellectual-property work: invalidity, infringement and freedom-to-operate analysis. (law.com) That matters because those workflows are document-heavy, evidence-sensitive and costly enough that many companies leave patents unenforced or under-analyzed. (ycombinator.com) ### Why would investors fund a patent startup this early? Stilta is five months old and said this is its first outside funding. LawSites reported the company was founded in December 2025 by four former McKinsey engineers: Oskar Block, Tobias Estreen, Petrus Werner and Oscar Adamsson. (law.com) Y Combinator lists the company in its Winter 2026 batch. David Haber, an Andreessen Horowitz general partner, led the round for the firm, according to LawSites. That ties Stilta to a broader a16z push into legal software; Haber’s a16z profile lists Eve among his board companies. (lawnext.com) ### What, exactly, does Stilta’s product do? Stilta says users can enter a patent number and have AI agents search for prior art, map claims, pull prosecution history and assemble source-backed analysis. LawSites reported the system searches across 180 million patents, 250 million scientific publications and more than a trillion archived web pages, including through the Internet Archive’s Wayback Machine integration. (lawnext.com) TechCrunch reported CEO Oskar Block described the product as working like a team of lawyers, with multiple AI agents searching for conflicting patents, similar intellectual property, and filing and court histories. (lawnext.com) On Stilta’s website, the company says it is used by IP attorneys to find prior art, map claims and detect potential infringement, and that outputs are designed to be traceable and auditable. ### Why are enterprises and law firms both part of the sales pitch? Y Combinator says Stilta is used by leading IP law firms and in-house IP teams. The company’s website makes the same split explicit, describing workflows for competitor monitoring, portfolio assessment and patent-case preparation. (lawnext.com) That dual-market approach fits the product. A law firm may use the software to challenge or defend a patent in a dispute, while an in-house legal or IP team may use it to monitor competitors, assess licensing opportunities or decide whether a portfolio is worth enforcing. TechCrunch reported Block said many companies hold patents they have never enforced, licensed or properly analyzed because the work was too expensive. (techcrunch.com) ### Where does Stilta sit in the legal-tech market? LawSites said Block identified Patlytics and Solve Intelligence’s Charts product as close competitors. The same report said most other patent-AI tools have focused more on prosecution than on litigation work. (ycombinator.com) That distinction is important because litigation-grade patent analysis requires cited evidence, claim mapping and defensible reasoning, not just drafting assistance. Stilta’s website says the company built around privacy and enterprise controls, including a promise not to use customer data to train models. (techcrunch.com) ### What happens next after the seed round? Stilta says it is starting with patent litigation and broader intellectual-property workflows. The company is hiring for five roles, according to its Y Combinator page, and its website is actively offering demos to prospective customers. The next test is customer adoption across the two buyer groups Stilta has named: law firms and in-house enterprise IP teams. (lawnext.com) As of May 20, the company’s public materials point to those users, and its product pages center on infringement analysis, prior-art search and portfolio evaluation. (ycombinator.com) (stilta.com)