Comparison
Westlaw Precision AI vs Mi Assist Legal -- Which is right for your firm?
Westlaw Precision AI charges ~$155/mo per attorney add-on to Westlaw and runs on Cloud (Thomson Reuters). Mi Assist Legal runs on your own hardware -- one flat fee, no recurring seats, no data leaving your office.
TL;DR
The five-row answer.
| Dimension | Mi Assist Legal | Westlaw Precision AI |
|---|---|---|
| Deployment | On-premise, your hardware | Cloud (Thomson Reuters) |
| Price model | One-time deployment fee | ~$155/mo per attorney add-on to Westlaw |
| Data location | Your office network, always | Thomson Reuters cloud infrastructure |
| Best for firm size | 5-30 attorneys | Firms already on Westlaw subscriptions |
| Offline capable | Yes -- fully offline | No -- internet required |
Deployment Model
Cloud vs on-premise. What it actually means.
Westlaw Precision AI is Thomson Reuters's AI feature layer for its Westlaw legal research database. It adds natural language querying, AI-generated research memos, and document comparison to the Westlaw platform. Like Lexis+ AI, it is a cloud service requiring an active Westlaw subscription.
Westlaw Precision AI searches the Thomson Reuters legal database: court opinions, statutes, regulations, law review articles, and Westlaw's proprietary research tools. When an attorney enters a research question, the system searches published legal sources, not the firm's own documents. If you need to ask what a deponent said in a specific transcript or find a clause buried in 200 discovery documents, Westlaw Precision AI does not address that workflow.
Thomson Reuters is also the parent company of CoCounsel, which serves a different function: CoCounsel is positioned for document-level AI work including drafts and summaries. Both products are cloud services under the Thomson Reuters umbrella, meaning data flows through Thomson Reuters infrastructure regardless of which product is in use.
Pricing at Scale
10-attorney firm. 5-year total cost.
Per-seat pricing compounds every year. Mi Assist Legal is a one-time deployment -- the math becomes obvious over time.
| Period | Mi Assist Legal | Westlaw Precision AI |
|---|---|---|
| Year 1 (10 attorneys) | $6,000 setup | $18,600 (add-on estimate) |
| Year 2 | $0 (no per-seat) | $18,600 |
| Year 3 | $0 | $18,600 |
| Year 4 | $0 | $18,600 |
| Year 5 | $0 | $18,600 |
| 5-Year Total | ~$6,000 | ~$93,000 |
Westlaw Precision AI pricing estimated at approximately $155/attorney/month based on reported pricing; actual pricing depends on your existing Westlaw contract tier. These figures exclude base Westlaw subscription costs, which are significant on their own.
Feature Comparison
Honest feature breakdown.
| Feature | Mi Assist Legal | Westlaw Precision AI |
|---|---|---|
| Searches your case files | Yes, your uploaded documents | No, Westlaw database only |
| Searches case law database | Only uploaded case law docs | Full Westlaw database |
| Data location | On-premise, your network | Thomson Reuters cloud |
| Pricing model | One-time deployment fee | Per-seat add-on to Westlaw |
| Offline capable | Yes, fully | No, requires internet |
| Source citations | Yes, document + page number | Yes, Westlaw citations |
| ABA 1.6 by architecture | Yes, no data leaves office | Vendor policy dependent |
| Requires existing subscription | No | Yes, requires Westlaw base |
Decision Guide
The honest answer.
Choose Westlaw Precision AI if:
- --Your primary need is AI-assisted case law research within the Westlaw platform.
- --You already pay for Westlaw and want to layer AI queries on published legal sources.
- --KeyCite citation validation and Westlaw's proprietary secondary sources are central to your research workflow.
- --Research memo generation from Westlaw database searches is a high-value workflow for your associates.
Choose Mi Assist Legal if:
- Your bottleneck is finding information in case files and internal documents, not researching case law.
- You need document queries to remain on-premise with no data leaving your network.
- Adding more per-seat fees on top of an existing Westlaw subscription is not feasible.
- You want a standalone AI that does not require a subscription to any legal database.
FAQ
Common questions.
What is Westlaw Precision AI specifically?
Westlaw Precision AI is an AI research assistant layer built on top of Thomson Reuters's Westlaw legal database. It allows attorneys to ask natural language questions and receive AI-generated research summaries with citations from the Westlaw database. It is an add-on to existing Westlaw subscriptions, not a standalone product.
Does Westlaw Precision AI analyze documents I upload?
Westlaw Precision AI primarily searches the Westlaw database. Thomson Reuters has added some document upload and analysis features, but the core function is natural language queries against published legal sources. For comprehensive search of your own uploaded case files, depositions, and client documents, a purpose-built document AI like Mi Assist Legal is the appropriate tool.
How does Mi Assist Legal handle privilege for uploaded documents?
Because Mi Assist Legal processes documents entirely on your own hardware, attorney-client privilege and work product protections are maintained structurally. Documents never leave your network. There is no third-party processing, no vendor with access to your content, and no transmission event. This is a technical safeguard, not a contractual one.
What document formats does Mi Assist Legal accept?
Mi Assist Legal ingests PDF, DOCX, TXT, and email exports. The system processes court filings, deposition transcripts, medical records, contracts, correspondence, and structured data exports. Documents are indexed locally using a vector database that enables semantic search across your entire document library.
Can Mi Assist Legal work alongside a Westlaw subscription?
Yes. Westlaw handles published case law research. Mi Assist Legal handles internal document search. For a firm doing litigation, you might use Westlaw Precision AI to research the controlling standard of care, then use Mi Assist Legal to find every instance that standard is mentioned in your case files, expert reports, and correspondence.
Next Step
See how Mi Assist Legal works for your firm.
15-minute call. Live demo on a real case file. We will walk through setup, pricing, and whether Mi Assist Legal fits your workflow.