AI in Law & Legal Services · AI Legal Research Tools

Do Westlaw and Lexis have AI-powered research features?

Yes — both Westlaw and Lexis, the two largest legal research platforms, have introduced generative AI features that let users ask natural-language questions and receive cited, synthesized answers.

Legal disclaimer

This page provides general information only and is not legal advice. Laws vary by jurisdiction and change over time. Consult a licensed attorney in your jurisdiction before making decisions based on this content.

Key takeaways

Thomson Reuters (Westlaw) and LexisNexis have each rolled out generative AI features built on their respective case law and statutory databases.
These features generally allow natural-language questions, draft generation, and document summarization in addition to traditional search.
Both companies emphasize that AI outputs are linked back to citations within their databases so users can verify the underlying source.
Availability of specific AI features can depend on a firm's subscription plan and the product tier it has access to.

Two dominant platforms, two AI rollouts

Westlaw, owned by Thomson Reuters, and Lexis, from LexisNexis, have long been the two dominant legal research platforms used by law firms, courts, and law schools. As generative AI matured, both companies moved to integrate AI-powered features into their existing products rather than launching entirely separate tools. The result is that many users of these established platforms now have access to natural-language question answering, drafting assistance, and summarization capabilities layered on top of the same underlying legal databases these companies have built over decades.

What the AI features generally offer

Both companies’ AI offerings generally allow a researcher to type a question in plain English and receive a synthesized answer that cites specific cases, statutes, or secondary sources from within the platform’s database, rather than an open-ended internet search. Additional capabilities commonly include summarizing lengthy opinions, drafting portions of legal documents, and helping identify relevant authority more quickly than manual keyword searches alone. Because these features are built on each company’s proprietary, continuously updated legal database, the citations they generate are intended to be checkable against real primary sources within the platform.

Why the underlying database still matters

The value proposition both companies emphasize is that their AI features are grounded in verified legal databases, which is meant to reduce the risk of the AI generating citations to cases that don’t exist — a well-documented problem with general-purpose AI chatbots that lack a legal-specific, verified database to draw from. Even so, both companies generally caution that users should review the underlying cited sources rather than relying solely on the AI-generated summary, consistent with the broader legal research practice of verifying authority before using it in a filing.

Bottom line

Both Westlaw and Lexis have added generative AI research features to their existing platforms, allowing natural-language questions and AI-generated summaries grounded in their respective legal databases, though exact capabilities and access depend on subscription plan and continue to evolve.

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Important caveats

Specific feature names, pricing, and availability change over time and vary by subscription tier, so details should be confirmed directly with the provider.
This is general information, not an endorsement or a comprehensive comparison of either platform's current offerings.

Frequently asked questions

Are Westlaw's and Lexis's AI features the same?

No — each company has developed its own generative AI tools built on its own database and technology, so specific capabilities and branding differ between the two platforms.

Do these AI features replace the need for traditional search?

Generally no — traditional keyword and Boolean search remains available alongside the newer AI-assisted natural-language features on both platforms.

Can smaller firms access these AI research tools?

Access typically depends on a firm's specific subscription plan, and both companies have expanded AI features across different customer tiers over time.

Sources

[1]Legal research platform and technology information — Thomson Reuters
[2]Legal research platform and technology information — LexisNexis

Written by Editorial Team

Last updated July 28, 2026

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