Thomson Reuters AI Battles ChatGPT for Legal Tech Dominance

The old saying was that software is eating the world. Now, it seems AI is eating software, and in the specialized field of legal technology, established giants like Thomson Reuters are fighting to stay at the top of the food chain.

At the heart of its strategy, the company is leveraging one of the largest private collections of legal data on the planet. By infusing this proprietary information with generative AI, Thomson Reuters is rolling out advanced products like Westlaw Advantage and CoCounsel, designed to automate and enhance legal work. While this move initially excited investors, the emergence of powerful new rivals has raised questions about the company's long-term AI strategy.

The most pressing question is whether its specialized tools can deliver intelligence superior to what general-purpose models like ChatGPT already offer. Is Thomson Reuters creating a truly unique platform, or is it building a sophisticated 'model wrapper' with a limited shelf life?

A Competitive Edge Under Scrutiny

The company recently made its case during an earnings call, but Wall Street's reaction was lukewarm. Thomson Reuters saw its shares fall, continuing a downward trend from the summer. Despite this, the company reported strong underlying growth, with its legal unit's organic revenue climbing 9% to $700 million. Its AI-powered CoCounsel products were a key driver, posting double-digit growth.

Thomson Reuters CEO Steve Hasker. Photo: Patrick MacLeod/Penske Media via Getty Images

On the call, CEO Steve Hasker emphasized that the company's AI 'agents' are progressively taking on more complex legal tasks. He argued that the company's defensible edge comes from the powerful combination of its extensive law library and expert editorial content, which he described as "difficult, if not impossible, to replicate."

New Challengers Enter the Ring

Thomson Reuters is now navigating both offensive and defensive maneuvers in this lucrative tech sector. While it has been a dominant force for decades, the generative AI boom has opened the door for new competitors backed by significant venture capital.

This summer, a major challenger emerged when RELX's LexisNexis, another legal data heavyweight, formed a strategic alliance with the AI startup Harvey. This partnership combines a massive corpus of legal information with a cutting-edge technical team. Shortly after, the legal operations platform Clio acquired legal data specialist vLex for a reported $1 billion, signaling another significant consolidation in the space. Hasker, however, dismissed the soaring valuations and bold claims of AI startups as "squishy," asserting that CoCounsel's adoption rate is outpacing its rivals.

Building a Defensible AI Moat

At the core of Thomson Reuters' defense is its unique data advantage. The company's moat, as framed by its CEO, is the fusion of its Westlaw legal data with a rigorous human-in-the-loop validation process. This is crucial in an industry where accuracy and reliability are non-negotiable.

"Litigation is high-stakes work with no room for error and significant consequences for being wrong," Hasker stated. Westlaw processes over 300 million documents annually from countless court systems. An internal team of attorneys and editors refines this raw data, writing headnotes, verifying facts, and tagging key issues to create court-safe guidance. With roughly 85% of primary documents in Westlaw receiving these editorial enhancements, the company is now focused on moving beyond simple data retrieval and summarization to offer generative services that assist with more valuable, agentic workflows.

The Shadow of OpenAI

The question looming over the entire legal tech industry is what happens if OpenAI decides to enter the market directly. The AI giant could potentially launch its own vertically-integrated application for law firms, a move that would send shockwaves through the ecosystem. While there are no immediate plans, recent OpenAI demos on contract review, a core legal tech function, have sparked concern.

Such a move would be complex, as it could cannibalize the business of customers like Thomson Reuters, whose CoCounsel product utilizes OpenAI's GPT models. Further complicating matters, OpenAI is an early investor in Harvey, a direct competitor.

Even without a dedicated legal product, OpenAI acts as a 'gravitational competitor.' Lawyers are already using ChatGPT, and Harvey's CEO has noted that customers benchmark specialized legal AI against the latest general-purpose models. This dynamic means OpenAI can reshape the market with every new update, forcing others to constantly prove their value. Hasker’s counterargument is that in a high-stakes field, depth and specialization will prevail. He believes specialized AI tools built on unique, accurate data will ultimately win against general-purpose offerings.

"Customers are starting to understand the difference," he said, before concluding with a dose of realism. "Anyone who will tell you they know exactly what's going to happen in this environment is probably slightly deluded."