Harvey vs Casetext (CoCounsel)

Harvey and Casetext (now part of Thomson Reuters as CoCounsel) both target the same buyer — large firms and corporate legal — but from opposite directions. Harvey was built AI-first and sold into elite firms. Casetext came from legal research and was acquired by TR in 2023, giving it the Westlaw spine. Picking between them is really picking between “frontier model on your firm’s data” and “deep legal research database with AI on top.”

Where Harvey wins

• Custom model on firm precedent. Harvey trains on your firm’s documents and house style. Casetext’s CoCounsel uses the underlying TR research corpus, but firm-specific tuning is shallower.
• Bespoke workflows. Harvey’s Workflows feature lets firms encode their own diligence checklists, regulatory matrices, and drafting playbooks. CoCounsel ships with fixed skills (Review Documents, Legal Research, Contract Analysis).
• Frontier-model parity. Harvey was first to ship GPT-4-class capability for legal and has stayed close to the frontier. CoCounsel leans on the TR stack and tends to lag on raw model quality.

Where Casetext wins

• Westlaw integration. Citations land in Westlaw, KeyCite signals show, and your research trail is unified. Harvey’s research is competent but doesn’t replace a real legal database.
• Pricing accessibility. CoCounsel is reachable for solo and small-firm budgets. Harvey isn’t — it’s enterprise sales only.
• Legal research depth. If your work is litigation-heavy and case law-driven, Casetext’s research surface is materially better. Harvey treats research as one workflow among many.

Pricing reality

Harvey is six-figure enterprise contracts. Casetext / CoCounsel is per-seat and bundled into Thomson Reuters’ broader sales motion — if you already have Westlaw or Practical Law, the marginal cost is reasonable. Many AmLaw firms run both: Harvey as the bespoke workflow layer, CoCounsel for research and citation work tied to Westlaw.

Verdict

• Pick Harvey if you want a frontier-model platform tuned on your firm’s own work, you have an enterprise budget, and your differentiation is bespoke workflows your competitors can’t replicate.
• Pick Casetext if your work is research- and litigation-heavy, you already live in the Westlaw / TR ecosystem, and you want AI that sits on top of authoritative legal data.
• Use both if you’re a top-50 firm — Harvey for proprietary workflows, CoCounsel for research and citation.

The single mistake to avoid: assuming “frontier AI” beats “legal research database integration” for litigation work. It doesn’t, yet.