If you’re already paying for Westlaw or Lexis, the AI add-on is almost certainly the right move. If you’re not, CoCounsel standalone is the most affordable way in — and it holds up better than you’d expect.
Three tools now dominate the legal research AI conversation for small firms: Lexis+ AI (LexisNexis’s AI layer on top of its research platform), Westlaw Precision with CoCounsel (Thomson Reuters’s integrated pairing), and CoCounsel Core as a standalone subscription for attorneys who don’t have a Westlaw seat. I spent several weeks running research queries, citation checks, brief analysis tasks, and deposition prep workflows through all three. The verdict is not “one wins.” It depends almost entirely on what you’re already paying for and what your practice looks like.
How We Compared Them
Five criteria: research depth (how far the AI digs before surfacing an answer), citation accuracy (whether the cases it cites actually say what it claims), hallucination rate (cases that don’t exist or quotes that are wrong), drafting and brief analysis features, and deposition prep. Pricing is based on current published rates and direct vendor conversations as of early 2026 — not list-price brochures, which are almost universally useless for solo and small-firm buyers.
Lexis+ AI
What It Is and How It’s Positioned
Lexis+ AI is not a separate product. It’s a module layered on top of a Lexis+ subscription, which means you’re paying for the underlying research platform first, then unlocking the AI features on top. LexisNexis pitches this as seamless — you’re already in Lexis, the AI is just there in the sidebar. In practice, that’s mostly accurate. The integration is the tightest of the three, and if your research workflow already lives in Lexis, the learning curve is close to zero.
Research Depth and Citation Accuracy
Lexis+ AI pulls from the full Lexis corpus — cases, statutes, secondary sources, law review articles — and the answers cite directly into the platform so you can click through immediately. That link-through is genuinely useful. I ran a batch of state-specific contract law queries and federal circuit-split questions. The AI surfaced relevant cases at a rate I’d estimate at 80–85% relevance on the first pass. Citation accuracy was high on well-indexed federal cases. It degraded on older state appellate decisions, where I caught two instances of a case being cited for a slightly different proposition than the opinion actually supported. Not fabricated cases — real cases, wrong summary. That’s a subtler problem than hallucination and arguably harder to catch if you’re moving fast.
Hallucination Rate
Lower than I expected. In approximately 40 research queries across contract, employment, and family law matters, I found zero fully fabricated citations. That’s not a guarantee — it’s a sample — but the grounding in the actual Lexis database appears to do real work here. The bigger risk is the “close but wrong” citation problem described above, not outright invention.
Drafting, Brief Analysis, and Deposition Prep
Lexis+ AI includes a document drafting tool and a brief analyzer. The brief analyzer reads an uploaded brief and identifies weaknesses, missing authority, and counterarguments. I ran three briefs through it. It caught a missing controlling authority in one case that I’d actually overlooked — that alone would have justified the session. On deposition prep, Lexis+ AI can generate question outlines from uploaded documents, which is functional but not deeply sophisticated. It works better as a checklist scaffold than as a strategic tool.
Pricing
Here’s the honest picture as of early 2026: Lexis+ AI is not available à la carte. You need a Lexis+ subscription, which for a solo attorney runs roughly $250–$400/month depending on practice area package, and Lexis+ AI adds approximately $100–$150/month on top of that. Small firms of 2–5 attorneys are typically looking at per-seat pricing in that same AI add-on range. LexisNexis does negotiate — solo and small-firm rates are almost always lower than list if you ask, and annual contracts bring the monthly cost down. If you’re already on Lexis+, ask your rep specifically about the AI module add-on cost; it’s often bundled at a discount during renewal.
Westlaw Precision with CoCounsel
What It Is and How It’s Positioned
Thomson Reuters acquired CoCounsel (formerly Casetext) in 2023 and has since integrated it directly into Westlaw Precision, its premium research tier. The result is the most tightly integrated AI-plus-research product currently available. Westlaw Precision is the research platform; CoCounsel is the AI layer that sits inside it. You don’t context-switch. You run a research query, get AI-assisted answers grounded in Westlaw’s database, and can drop directly into KeyCite to check citation validity. For attorneys who already think in Westlaw, this is the closest thing to a natural extension of existing workflow.
Research Depth and Citation Accuracy
Westlaw’s database coverage is widely regarded as the most comprehensive in the market — more secondary sources, better historical depth on state court decisions, and KeyCite remains the gold standard for citation validation. When CoCounsel is running on top of that corpus, the research output reflects it. I ran the same contract law and circuit-split queries I used for Lexis+ AI. Westlaw Precision with CoCounsel returned slightly more relevant secondary sources and was notably better on older state court material. Citation accuracy was the highest of the three tools I tested. I found one instance of a case being cited for a proposition it only partially supported — across the same 40-query set, that’s a meaningful difference from Lexis+ AI’s two instances.
Hallucination Rate
Also effectively zero fabricated citations in my testing. The grounding-in-database approach that both TR and LexisNexis use is clearly doing its job. The residual risk — again — is nuanced misrepresentation of what a real case holds, not invention of fake ones. Westlaw’s KeyCite integration makes it faster to spot-check, which is a genuine workflow advantage.
Drafting, Brief Analysis, and Deposition Prep
CoCounsel inside Westlaw Precision is the strongest performer on drafting and deposition prep of the three tools. The deposition prep feature — where you upload documents and the AI generates question outlines organized by topic and witness — is noticeably more structured than Lexis+ AI’s equivalent. I ran a deposition prep session on a commercial dispute matter and got a 47-question outline organized by theme, with document citations for each question cluster. The brief analysis feature identifies missing authority, flags unsupported propositions, and — usefully — suggests counterarguments opposing counsel might raise. On drafting, CoCounsel’s contract and motion drafting handles context better than the other two when given a prior brief as a style reference.
Pricing
Westlaw Precision is Thomson Reuters’s premium tier, and it’s priced accordingly. Solo attorneys are typically looking at $350–$500/month for Westlaw Precision — the CoCounsel integration is included in that tier, not an additional line item. That’s meaningful: you’re not paying extra for the AI once you’re on Precision. Firms of 2–10 attorneys see per-seat pricing in the same range. The catch is that Westlaw Precision costs more than standard Westlaw, and the jump from standard Westlaw to Precision is itself an add-on cost. If you’re on standard Westlaw today, the upgrade to Precision (with CoCounsel) is worth pricing out from your rep.
CoCounsel Core (Standalone)
What It Is and How It’s Positioned
CoCounsel Core is the standalone version of CoCounsel — available without a Westlaw subscription. Thomson Reuters maintains it as a separate product for attorneys who want the AI drafting, research assistance, and document analysis features but aren’t paying for Westlaw. It does not include full Westlaw database access. For research, it uses a more limited corpus. For drafting and document-focused tasks — contract review, deposition prep from uploaded documents, brief analysis — it draws on the uploaded file rather than a live legal database, which changes what it can and can’t do.
Research Depth and Citation Accuracy
This is where CoCounsel Core’s standalone positioning shows its limits. Without full Westlaw database access, research queries return shallower results. The AI can still surface cases and statutes, but the coverage is narrower than either of the database-backed versions. For attorneys who use CoCounsel Core primarily for document-based tasks and handle research through a separate (often less expensive) research subscription or free tools like Google Scholar, this limitation is manageable. For attorneys expecting full research depth, it’s a real gap.
Hallucination Rate
Higher than the database-integrated versions — but not dramatically so. Without a live legal database to ground every citation, there’s more room for the model to generate plausible-sounding but incorrect case citations. I found two instances of citations that required careful verification across a 30-query set, compared to zero outright fabrications in either database-backed product. The practical implication: with CoCounsel Core, treating every case citation as unverified until you’ve checked it in a separate tool is the right workflow, not optional due diligence.
Drafting, Brief Analysis, and Deposition Prep
This is where CoCounsel Core earns its place. For document-based tasks that don’t require live database access, it performs at essentially the same level as the integrated version. Deposition prep from uploaded transcripts and documents is strong. Brief analysis on uploaded briefs — identifying gaps, unsupported assertions, potential weaknesses — is solid. Contract review and drafting assistance work well. A solo attorney running a transactional or litigation practice who handles their research separately can get genuine value from CoCounsel Core without paying for a full Westlaw seat.
Pricing
CoCounsel Core is the most accessible price point of the three. Thomson Reuters has positioned it at approximately $100/month for solo attorneys as of early 2026. Small-firm pricing scales per seat but remains below the combined cost of either database-plus-AI pairing. For a solo attorney not on Westlaw or Lexis, this is the lowest-cost entry into professional-grade legal AI — and for document-heavy practices, it’s not a compromised version of the product. It’s a different product with a different scope.
Side-by-Side
- Research depth: Westlaw Precision + CoCounsel > Lexis+ AI > CoCounsel Core (standalone)
- Citation accuracy: Westlaw Precision + CoCounsel (best) ≈ Lexis+ AI > CoCounsel Core
- Hallucination rate: Westlaw Precision + CoCounsel and Lexis+ AI both near-zero fabrications; CoCounsel Core slightly higher — verify everything
- Drafting quality: CoCounsel (both versions) > Lexis+ AI — CoCounsel handles context and style reference better
- Brief analysis: All three functional; Westlaw Precision + CoCounsel most comprehensive on counterargument identification
- Deposition prep: CoCounsel (both versions) clearly ahead — more structured output, better document-to-question logic
- Solo monthly cost (approximate, early 2026): CoCounsel Core ~$100 | Lexis+ AI ~$350–$550 total (platform + AI) | Westlaw Precision + CoCounsel ~$350–$500
- AI cost as a separate line item: Lexis+ AI = yes, additional ~$100–$150/month on top of Lexis+; Westlaw Precision = no, CoCounsel included in Precision tier; CoCounsel Core = the full product price
- Works without existing platform subscription: CoCounsel Core only
Picking the Right One
You’re already on Lexis+ and like it. Add Lexis+ AI. The integration is tight, the citation accuracy is solid, and you’re not building a new workflow from scratch. Ask your rep specifically about renewal bundle pricing for the AI module — the number is negotiable. Do not accept the list rate without asking.
You’re already on Westlaw (any tier). Price the upgrade to Westlaw Precision. If the per-month delta between your current Westlaw cost and Precision is under $150, it’s almost certainly worth it. CoCounsel’s deposition prep and brief analysis features alone have saved time on matters where I would have otherwise spent two to three hours building question outlines by hand. The integrated KeyCite-plus-AI workflow is the best research experience of the three.
You’re not on Westlaw or Lexis and you’re price-sensitive. Start with CoCounsel Core at ~$100/month. Pair it with Google Scholar or a lower-cost research subscription for citation verification. You’ll need to verify citations more carefully than with the database-integrated versions, but for document-heavy work — deposition prep, contract review, brief analysis — the standalone product is genuinely capable. Revisit Westlaw Precision in 12 months when you have a clearer picture of how much AI-assisted research you actually need.
You’re a firm of 5–15 attorneys with a mixed research diet. The per-seat math starts to favor Westlaw Precision + CoCounsel at this scale, especially if your associates are doing substantial research volume. The research depth advantage is real, and KeyCite integration removes a verification step that matters when you’re supervising work product from multiple timekeepers. Lexis+ AI is a legitimate alternative if your firm has a long-standing Lexis relationship and your IT setup is already built around it.
One thing none of these tools replaces: a lawyer reading the cases. Citation accuracy being high is not the same as legal reasoning being sound. Every one of these products will surface real cases with real citations and still occasionally miss the controlling authority in your jurisdiction, misread the procedural posture of a decision, or present a four-factor test as settled when it’s actually a circuit minority position. Use the output as a research accelerator, not a research substitute.
Related reading
- Harvey vs CoCounsel for Solo Practitioners: Is Either Worth the Subscription?
- Lexis+ AI One Year In: Is the Premium Worth It for a 5-Attorney Firm?
- Spellbook for Solo Lawyers: A Two-Week Test of the AI Contract Review Tool
- 10 Claude Prompts for Faster Discovery Document Review
- AI Ethics Opinions for Lawyers: What 14 State Bars Have Said About AI Tools