Comparison
Spellbook vs Mi Assist Legal -- Which is right for your firm?
Spellbook charges $99-149/mo per attorney and runs on Cloud (Microsoft Word add-in). 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 | Spellbook |
|---|---|---|
| Deployment | On-premise, your hardware | Cloud (Microsoft Word add-in) |
| Price model | One-time deployment fee | $99-149/mo per attorney |
| Data location | Your office network, always | Spellbook / Azure cloud |
| Best for firm size | 5-30 attorneys | Transactional attorneys focused on contract drafting |
| Offline capable | Yes -- fully offline | No -- internet required |
Deployment Model
Cloud vs on-premise. What it actually means.
Spellbook is a Microsoft Word add-in that brings AI-assisted contract drafting directly into the Word editing experience. It is built on GPT-4 and allows attorneys to draft clauses, negotiate redlines, and get plain-language explanations of contract provisions without leaving Word. It is well-regarded in transactional law for its tight Word integration.
Spellbook and Mi Assist Legal serve meaningfully different use cases. Spellbook is a drafting tool. It helps attorneys write and revise contracts faster. Mi Assist Legal is a document search tool. It helps attorneys find information across large collections of existing documents. A transactional attorney who drafts contracts daily would find Spellbook useful; a litigation attorney who needs to search 200 depositions and 5,000 pages of discovery documents needs Mi Assist Legal.
Where they overlap is in the fundamental question of data handling. When an attorney pastes contract language into Spellbook's Word add-in, that text is transmitted to Spellbook's cloud infrastructure for processing. For contract drafting of a non-sensitive commercial lease, this may be acceptable. For work involving confidential settlement terms, client financial details, or proprietary business arrangements, the data transmission raises the same ABA 1.6 analysis that applies to all cloud AI tools.
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 | Spellbook |
|---|---|---|
| Year 1 (10 attorneys) | $6,000 setup | $11,880-17,880 |
| Year 2 | $0 (no per-seat) | $11,880-17,880 |
| Year 3 | $0 | $11,880-17,880 |
| Year 4 | $0 | $11,880-17,880 |
| Year 5 | $0 | $11,880-17,880 |
| 5-Year Total | ~$6,000 | $59,400-89,400 |
Spellbook pricing at $99-149/attorney/month as publicly listed. 10-attorney calculation based on published per-seat rates. Mi Assist Legal is a one-time deployment with no recurring fees.
Feature Comparison
Honest feature breakdown.
| Feature | Mi Assist Legal | Spellbook |
|---|---|---|
| Primary use case | Document search and Q&A | Contract drafting and review |
| Works with Word | No native Word add-in | Yes, native Word integration |
| Data location | On-premise, your network | Spellbook / Azure cloud |
| Searches all case files | Yes, across all uploaded docs | No, single document at a time |
| Pricing model | One-time deployment fee | Per-seat monthly |
| Offline capable | Yes, fully | No, requires internet |
| ABA 1.6 by architecture | Yes, no data leaves office | Vendor policy dependent |
| Source citations | Yes, document + page number | Contract clause references |
Decision Guide
The honest answer.
Choose Spellbook if:
- --Your practice is primarily transactional and you draft commercial contracts, NDAs, or purchase agreements daily.
- --You want AI suggestions surfaced inline in Microsoft Word without switching to another tool.
- --Contract clause libraries and AI-suggested redlines are your highest-value use case.
- --Spellbook's per-seat cost is manageable for your number of transactional attorneys.
Choose Mi Assist Legal if:
- You need to search across large collections of case files, discovery documents, or client records.
- Your practice includes litigation, family law, PI, or any area requiring deep document review.
- All AI processing must stay on your hardware with no cloud transmission.
- You want a single flat-fee deployment that covers unlimited attorneys without adding more seats.
FAQ
Common questions.
Can Spellbook search across multiple documents?
Spellbook is designed to work on individual contracts within Microsoft Word. It analyzes the document you have open and provides AI assistance within that context. It does not index or search across a library of documents. For cross-document search with semantic queries, a document AI with vector search like Mi Assist Legal is the appropriate tool.
Does Mi Assist Legal help with contract drafting?
Mi Assist Legal excels at answering questions from documents you have uploaded. If you have a folder of prior contracts, you can ask "What payment terms have we used in past commercial leases?" and get specific answers with citations. However, it does not generate new contract language from scratch the way Spellbook does. The tools complement rather than replace each other for transactional practices.
Is Spellbook compliant with ABA Rule 1.6?
Spellbook processes text through its cloud infrastructure when an attorney uses the add-in. For work involving sensitive client information, attorneys should review Spellbook's data handling policies and determine whether that processing is consistent with their confidentiality obligations. Many transactional attorneys use Spellbook for template or form agreement work and apply more caution with confidential client matters.
What types of law firms benefit most from Mi Assist Legal?
Mi Assist Legal provides the highest value for practices with large document volumes per case: personal injury (medical records, depositions), family law (financial disclosures, correspondence), employment law (EEOC filings, email threads), real estate (title documents, environmental reports), and immigration (visa applications, country condition reports). Any practice where attorneys spend significant time locating specific information within large document sets benefits from semantic search.
How many documents can Mi Assist Legal index?
The system scales with hardware. A standard Mac Mini deployment handles document libraries from a few thousand to several hundred thousand pages. The vector database (ChromaDB or Qdrant) is configured at deployment based on your estimated document volume. For very large practices with millions of pages, the deployment team recommends a more powerful on-premise server.
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.