Harvey AI vs Custom AI System: Which Is Right for a Mid-Size Law Firm?
Quick Take / Direct Answer
Harvey is a foundation-model legal AI trained on general legal datasets. A custom AI system is trained on your firm's own documents — your specific contracts, precedents, and matter history. Harvey delivers broad legal reasoning; a custom system delivers accurate institutional knowledge retrieval. For firms where knowing your firm's own work is the priority, custom AI consistently outperforms Harvey on firm-specific queries.
What Harvey AI Actually Does
Harvey is a generative AI platform purpose-built for legal work. It is trained on legal corpora — case law, statutes, legal literature — and fine-tuned to understand legal language and reasoning patterns. Attorneys can use Harvey to draft, research general legal questions, summarise documents, and generate first-draft memos.
Harvey's strength is general legal intelligence. Ask Harvey about the principles of force majeure under English law and it will give an informed, competent answer. Ask Harvey what your firm's standard force majeure position was in your last 50 commercial contracts and it cannot answer — because it has never seen your firm's contracts.
What a Custom AI System Does
A custom AI system — built using a RAG architecture on your firm's document library — knows what Harvey does not: your firm's specific work.
It can answer: "What indemnity language did we use in our last technology services agreement with a financial services client?" or "How did we handle limitation of liability in the ACME matter?" or "What is our standard intellectual property ownership position for consulting engagements?"
These questions are unanswerable by any general-purpose legal AI. They require access to your firm's specific documents.
Feature Comparison
| Feature | Harvey AI | Custom AI System (Govistudio) |
|---|---|---|
| Trained on your firm's documents | ✗ | ✓ |
| Knows your firm's standard positions | ✗ | ✓ |
| General legal reasoning | ✓ Excellent | Good (via GPT-4o) |
| Data processed on firm's infrastructure | ✗ | ✓ Private deployment |
| Per-seat licensing cost | ~$500–2,000+/attorney/year (est.) | $0 (owned system) |
| Build cost | $0 | $18,000–$45,000 |
| Setup time | Days–weeks | 5–8 weeks |
| DMS integration (iManage, NetDocuments) | Limited | ✓ Full API |
| Source citation from firm's documents | ✗ | ✓ |
| Customisable to practice area | Limited | ✓ Fully |
| Long-term per-attorney cost (3-year) | $1,500–6,000+/attorney | $400–1,000/attorney (amortised) |
Which Firms Should Choose Harvey?
Harvey is the right choice when:
- The primary need is general legal drafting assistance, memo generation, and research on general legal questions
- The firm does not have a large, specialised document library requiring institutional knowledge retrieval
- Speed of deployment is the priority over firm-specific accuracy
- Budget is per-seat licensing only with no capital investment
Which Firms Should Choose Custom AI?
Custom AI is right when:
- The firm has valuable institutional knowledge locked in its document library (precedents, matter files, client correspondence)
- Attorneys need to search and retrieve from the firm's own work, not general legal knowledge
- Data privacy obligations require all processing on the firm's own infrastructure
- The firm wants an AI system it owns, not an ongoing per-seat licence
- Long-term cost efficiency matters (custom AI amortises; per-seat licensing scales linearly with headcount)
Can You Use Both?
Yes. Some firms use Harvey for general drafting assistance and a custom RAG system for institutional knowledge retrieval. These solve different problems and do not compete directly.
FAQs
Q: Does Harvey AI store our documents? A: Harvey processes documents submitted to it during a session. The data handling terms depend on your Harvey enterprise agreement — review carefully before submitting client documents.
Q: How much does Harvey AI cost? A: Harvey does not publish pricing publicly. Industry estimates for enterprise law firm contracts range from $500–$2,000+ per attorney per year depending on firm size, usage volume, and negotiation. Contact Harvey for a specific quote.
Q: Is a custom AI system better than Harvey for all law firms? A: No. For a firm whose primary AI need is drafting assistance and general legal research, Harvey may be the right tool. For a firm whose primary need is institutional knowledge retrieval from its own document library, custom AI outperforms Harvey on the specific use case that matters most.