Quick answer
All three are AI assistants built on top of a big legal database. CoCounsel Legal runs on Westlaw and Practical Law. Lexis+ with Protégé runs on LexisNexis content and checks citations with Shepard's. Vincent runs on vLex's global library and, since Clio bought vLex in November 2025, it is also the assistant inside Clio Work. If you already pay for Westlaw or Lexis, start with that vendor's AI. If you run your practice on Clio, or you work across many jurisdictions, put Vincent on your trial list. None of the three publishes a price.
On this page (10)
- What's the difference between CoCounsel, Lexis+ with Protégé, and Vincent?
- Is CoCounsel worth it if you already use Westlaw?
- Is Lexis+ with Protégé the better pick for Lexis subscribers?
- What does Vincent do, and is it still available?
- How much do CoCounsel, Lexis+ with Protégé, and Vincent cost?
- Which legal research AI should a small firm choose?
- Related guides
- FAQ
- Is any of this sponsored?
- Sources (all accessed 2026-10-14)
Everything below comes from each vendor's own pages, accessed October 14, 2026, unless we say otherwise. We haven't tested these tools hands-on, and we publish no star ratings.
Disclosure: Some listings on AI Tools For Law may be sponsored or include affiliate or referral links. Paid placements are always labeled "Sponsored," and payment never changes our verdicts. None of the links in this article are paid placements as of publication. Nothing here is legal advice. Check your own jurisdiction's ethics rules before using AI with client information.
What's the difference between CoCounsel, Lexis+ with Protégé, and Vincent?
The biggest difference is the library underneath each one. The AI features look similar on paper: plain-English questions, cited answers, drafting, and document review. What changes from tool to tool is the case law, the secondary sources, and the citator the AI draws on.
| CoCounsel Legal | Lexis+ with Protégé | Vincent (vLex, part of Clio) | |
|---|---|---|---|
| Content it draws on | Westlaw, Practical Law, and your own documents | LexisNexis case law, statutes, and secondary sources, plus practice notes and forms "across 25 practice areas" | vLex's library: "more than one billion editorially enriched documents across 110 jurisdictions" (Clio press release) |
| Citation checking | Linked citations to Westlaw content | Shepard's built into research and drafting | Fully cited memos with links to primary sources. Clio Work says a "built-in citator confirms every authority is current" |
| Drafting | Drafts in Microsoft Word; Westlaw Brief Builder | Drafts agreements, motions, briefs, complaints, and client letters | Litigation tools such as complaint analysis. Clio Work drafts in its own editor or in Word |
| Bulk document review | "Review up to 10,000 documents against 100 questions" | Secure document Vault | Contract and complaint review workflows |
| Trial | "Request free trial" | Free trial offered | Free trial on vLex; Clio's help center mentions a 30-day Clio Work trial |
| Published price | No (sales contact) | No (quote-based) | No (none found) |
Is CoCounsel worth it if you already use Westlaw?
Usually yes, at least for a trial. Thomson Reuters says CoCounsel Legal handles "research, analysis, and drafting from a single query," and it is "grounded in Westlaw, Practical Law, and your organization's own knowledge." If your associates already trust KeyCite and Practical Law, adding the AI layer on top avoids running a second research library.
The features the product pages emphasize:
- Deep Research, which "works through it step by step, retrieving relevant material and building context on your matter"
- Westlaw Brief Builder, which builds "litigation briefs from issue framing to argument structure"
- Drafting in Microsoft Word, reading your matter documents "to pull key facts and defined terms" and "redline against your standard"
- Bulk review of up to 10,000 documents against 100 questions, with the results in one table
Thomson Reuters also lists bundles such as "Westlaw Advantage with CoCounsel Essentials" and a separate CoCounsel Essentials tier. The pages we checked don't explain how those tiers differ in price, so ask a sales rep.
Is Lexis+ with Protégé the better pick for Lexis subscribers?
For a firm already on Lexis+, yes. Protégé is the same kind of upgrade CoCounsel is for Westlaw shops. LexisNexis notes the product was "formerly Lexis+ AI," so older articles may still use that name. The product page describes:
- Full drafting of "transactional agreements and contracts, as well as litigation motions, briefs, complaints, and client communications"
- Shepard's validation "directly within your research and drafting workflow"
- Practice notes, annotated forms, and drafting guidance "across 25 practice areas"
- Connections to iManage, SharePoint, NetDocuments, and other document systems, plus a secure document Vault
Pick the citator before you pick the chatbot. The AI layer changes every few months. Your research library and the habits built around it don't.
What does Vincent do, and is it still available?
Yes, it's still available. vLex's Vincent page is live, offers a free trial, and says Vincent is built for "big law firm, working in-house or running a small practice." Its research and litigation features include:
- Turning natural-language questions into answers with "full citations" and a "fully cited memo with direct links to primary sources"
- Multi-jurisdiction surveys, including "summaries of laws across all 50 U.S. states from a single query"
- Reviewing "opposing counsel's complaints" to flag "weaknesses, unsupported claims, and gaps in legal authority"
- Vincent Studio, which lets legal teams build their own custom workflows
The newer route in is Clio Work, Clio's AI workspace. Clio's help center says Vincent can read a selected matter's "full context from Clio Manage and take actions in Clio Manage on your behalf, such as updating tasks or creating new matters." We got that from a search snippet because the help center blocked our direct fetch. The Clio Work page also says client files are processed "under strict zero data retention (ZDR) agreements and are never used to train public AI models."
How much do CoCounsel, Lexis+ with Protégé, and Vincent cost?
None of them publishes a price. CoCounsel sends law firms to "Contact us about plans," Lexis+ with Protégé is quoted case by case, and we found no public price for Vincent or Clio Work. vLex's /pricing URL returned a 404 on October 14, 2026, and the Clio Work page shows no price. Clio's main pricing page lists Manage plans "starting at $49/user," but that is practice management, not Clio Work.
Which legal research AI should a small firm choose?
Follow the library you already use, and run a trial on a real (sanitized) research question before you commit.
Related guides
FAQ
Is Vincent AI still sold separately from Clio?
The vLex Vincent page is still live, with a free trial, and calls the product "Vincent by vLex (part of Clio)." Clio also presents Vincent as the assistant inside Clio Work. We didn't find a public price for either route.
Was Lexis+ AI renamed?
Yes. LexisNexis marks Lexis+ with Protégé as "Formerly Lexis+ AI."
Can these tools check their own citations?
Lexis+ with Protégé builds in Shepard's. CoCounsel links its citations to Westlaw content. Clio Work describes a built-in citator. None of that replaces your own cite-check before filing.
Does any of them publish pricing?
Not on the pages we checked on October 14, 2026. All three go through sales or a quote.
Is it ethical to use AI for legal research?
The ABA's Formal Opinion 512 (July 2024) says lawyers using generative AI must consider competence, confidentiality, communication, and reasonable fees. Check your own state bar's guidance too. This isn't legal advice.
Is any of this sponsored?
Not as of publication. If that changes, the listing will be labeled "Sponsored," and payment won't change the verdict.
Sources (all accessed 2026-10-14)
- CoCounsel Legal: https://legal.thomsonreuters.com/en/products/cocounsel-legal
- CoCounsel Legal features: https://legal.thomsonreuters.com/en/products/cocounsel-legal/features
- Westlaw: https://legal.thomsonreuters.com/en/products/westlaw
- Lexis+ with Protégé: https://www.lexisnexis.com/en-us/products/lexis-plus-protege.page
- Vincent by vLex: https://vlex.com/vincent-ai
- vLex news, "vLex Joins Clio in Landmark $1B Acquisition": https://vlex.com/news/vLex-Joins-Clio-in-Landmark-1B-Acquisition-And-Clio-Announces-Series-G-5B-Valuation
- Clio press release (Nov 10, 2025): https://www.clio.com/about/press/clio-completes-landmark-1b-vlex-acquisition-series-g-5b-valuation/
- Clio Work: https://www.clio.com/work/
- Clio help center, "Understand Clio Work" (quoted from a search result; direct fetch blocked): https://help.clio.com/hc/en-us/articles/48791655710235-Understand-Clio-Work
- Clio pricing: https://www.clio.com/pricing/
- ABA, "ABA issues first ethics guidance on a lawyer's use of AI tools" (July 29, 2024): https://www.americanbar.org/news/abanews/aba-news-archives/2024/07/aba-issues-first-ethics-guidance-ai-tools/
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