US legal AI has split into three camps: research assistants built on Westlaw, Lexis or vLex content, contract tools that live inside Microsoft Word, and practice-management add-ons that know your matters. Most are built for attorneys, and the right pick depends heavily on firm size and which research database you already pay for.
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For: Large firms and corporate legal teams
Assistant for research and drafting, Vault for reviewing thousands of documents at once, Workflows for repeatable tasks, and Deep Research for multi-step work. Dupple calls it overkill for firms under about 50 lawyers.
Price: Not published; quote only (2026-06)
For: Litigators whose firms already use Westlaw
Built on Westlaw primary law. Handles document review, deposition prep, contract analysis and research with citations linked to sources.
Price: $180 to $639 per user/month depending on tier, usually on top of a Westlaw subscription (2026-06)
For: Research-heavy firms
Combines Lexis content, the Protégé AI assistant and Shepard's citation checking in one workflow.
Price: Quote-based, generally $128 to $494 per user/month (2026-06)
For: Firms that want an alternative to Westlaw or Lexis
Research across millions of US documents, strong on multi-jurisdictional and comparative work. A lighter tier is free through more than 40 state bars as a member benefit.
Price: Around $399 per user/month for the core research package (2026-06)
For: Lawyers who draft and redline contracts in Word
A Word add-in that drafts clauses, flags risky language, generates redlines and applies negotiation playbooks. It is not a research platform. 7-day free trial.
For: Solo attorneys and small firms
Drafting, contract analysis and research across federal regulations, state law and case law. Holds SOC 2, ISO 27001 and HIPAA certifications.
Price: $499/month or $2,999/year for the individual plan, 7-day free trial (2026-06)
For: Firms already on Clio Manage
An AI layer inside Clio that uses your matters, documents and deadlines to summarize matters, pull out deadlines and draft client emails. A productivity assistant, not a research engine.
Price: About $39/user/month as an add-on to Clio Manage ($49 to $149/user/month) (2026-06)
| Combination | Why |
|---|---|
| Westlaw or Lexis AI + Word contract add-in | Research tools are grounded in case law, while Spellbook-style add-ins work where contracts are actually negotiated. Each covers what the other does not. |
| Vincent via your state bar + Paxton | Solos can start with the free bar-member tier for research and add a single-seat drafting tool before committing to an enterprise contract. |
| Practice management AI + research tool | Clio Duo knows your matters and deadlines; the research tool knows the law. Keep facts in one and authority in the other. |