Casetext

Casetext was a California-based provider of technology for legal professionals, founded in 2013 by Jake Heller, Pablo Arredondo and Laura Safdie. It began as a crowdsourced, free-to-access legal research resource — an effort to make case law and court documents broadly available and understandable — and later applied natural language processing and machine learning to legal research, producing tools such as Brief Analyzers and the CARA AI contextual search engine, which used the context of a user's own documents to surface on-point authorities.

The company's best-known product is CoCounsel, an AI legal assistant launched in 2023 and powered by GPT-4, which performed document review, legal research memos, deposition preparation and contract analysis. Casetext was granted early access to OpenAI's GPT-4 model, which it used to develop and refine legal use cases. At the time of its acquisition the company reported more than 10,000 law firm and corporate legal department customers and 104 employees, and stated that CoCounsel processed more than 2 billion words per day.

Thomson Reuters agreed in June 2023 to acquire Casetext for $650 million in cash and closed the transaction in August 2023. The standalone Casetext product was subsequently retired on April 1, 2025, with the underlying CoCounsel technology continuing under Thomson Reuters and packaged with its Westlaw ecosystem.

Founding story

The idea originated with Jake Heller, who noticed as a Stanford Law School student how difficult and expensive it was to retrieve legal information compared with everyday consumer search. After a clerkship on the First Circuit U.S. Court of Appeals and two years as an appellate associate at Ropes & Gray, he set out to build a free legal crowdsourcing tool — described as a Wikipedia for the law. The concept was accepted into Y Combinator (Summer 2013 batch), and Casetext launched in October 2013 backed by $1.8 million in seed funding. Heller was introduced to Pablo Arredondo, a former Kirkland & Ellis patent litigator, co-founder of the Sequoia-backed Occam Law and a fellow at the Stanford Center for Legal Informatics, by Paul Lomio, then associate dean of the Stanford law library; Laura Safdie, a Yale Law graduate, joined as the third co-founder.

Business model

Casetext sold AI-based legal research, document review and drafting software on subscription to law firms and corporate legal departments, ranging from solo practitioners and legal aid organizations to Am Law 100 firms. Following the acquisition, the successor CoCounsel offering was repackaged into per-user tiers, with fuller capabilities bundled with Thomson Reuters' Westlaw ecosystem rather than sold as the standalone product Casetext subscribers had used.

Traction

At acquisition Casetext had 104 employees and more than 10,000 law firm and corporate legal department customers, and reported CoCounsel processing over 2 billion words per day. Y Combinator's profile lists a team size of 50.

Latest developments

Thomson Reuters closed the $650 million cash acquisition on August 17, 2023, folding Casetext's brand, talent and products into its legal portfolio. On April 1, 2025, Thomson Reuters shut down the standalone Casetext product; it is no longer sold or supported, and CoCounsel — built on Casetext technology — continues as Thomson Reuters' legal AI offering, sold in per-user tiers alongside Westlaw.