Every managing partner's first question about legal AI: what does it cost?

Every managing partner's first question about legal AI: what does it cost? The answer ranges from $0 to $300,000/year depending on the tool, the tier, and whether you're a solo practitioner or an Am Law 50 firm. The legal AI market has matured enough that there's a legitimate tool at every price point.

This guide organizes every major legal AI tool by what you'll actually pay. No "contact us for pricing" runarounds. No hiding the ball. Real numbers based on current market data.

Free Tier: $0/Month

These tools cost nothing but come with significant limitations — data caps, no confidentiality guarantees, and basic features only.

- ChatGPT Free (OpenAI): Limited GPT-4 access, decent for basic legal research questions and simple drafting. Not suitable for client work — free tier data may be used for training. - Claude Free (Anthropic): Limited daily messages with Claude Sonnet. Good for testing capabilities before committing to Pro. Same training data concerns as any free AI tier. - Google Gemini Free: Basic AI assistant with Google search integration. Useful for quick factual lookups but weak on legal reasoning. - CaseText Free Research: Limited free case law searches. Good for law students and occasional researchers. - Fastcase (via bar membership): Many state bar associations include Fastcase access with membership. It's not AI-powered, but it's free legal research.

Bottom line on free tools: Fine for learning AI capabilities. Never use free tiers for actual client work — the confidentiality and accuracy risks aren't worth saving $20/month.

Under $50/Month: The Solo Practitioner Tier

This is the sweet spot for solos and small firms getting started with legal AI.

- Claude Pro ($20/month): Full access to Claude's most capable model with 200K context window. The best value in legal AI — handles research, drafting, contract review, and analysis at a professional level. Data isn't used for training on paid plans. - ChatGPT Plus ($20/month): GPT-4 access with plugins and file upload. Solid for general legal work but weaker than Claude on complex legal reasoning. - Google Gemini Advanced ($20/month): Access to Gemini Ultra with 1M token context window. Good for processing very large documents but less refined for legal-specific tasks. - Perplexity Pro ($20/month): AI-powered research with source citations. Useful for factual legal research and current events tracking. Not a substitute for Westlaw/Lexis. - Microsoft Copilot Pro ($30/month): AI integrated into Word, Outlook, and Teams. Good for document drafting and email management but limited legal-specific capabilities.

The recommendation at this tier: Claude Pro. For $20/month, you get the most capable AI reasoning engine available for legal analysis. Pair it with your existing Westlaw or Lexis subscription and you've got an AI-enhanced research and drafting workflow.

Under $200/Month: The Small Firm Tier

This tier adds legal-specific features, integrations, and better security.

- Clio Duo ($100-$150/month per user): AI built into Clio practice management. Billing narratives, matter analysis, client communication summaries. Best for firms already on Clio. - Claude Max ($100/month): Extended usage limits and priority access. Worth it for lawyers who hit Claude Pro's daily limits regularly. - CoCounsel (add-on to Westlaw, ~$100-$300/month): AI-powered legal research within Westlaw's database. The most natural upgrade for Westlaw users. - Lexis+ AI (~$100-$200/month add-on): Similar to CoCounsel but in the Lexis ecosystem. AI-powered research, drafting, and analysis. - Smokeball AI ($149-$199/month): Practice management with AI features for small firms. Automated document drafting and time tracking.

The recommendation at this tier: CoCounsel or Lexis+ AI as an add-on to your existing research platform, plus Claude Pro for general drafting and analysis work. Total: $120-$320/month for a comprehensive AI toolkit.

Enterprise Tier: $500-$3,000+/Month Per User

This is where the serious legal AI lives — purpose-built platforms with deep capabilities and enterprise security.

- Harvey AI ($1,500-$3,000/month per user): The most capable legal AI platform. Research, analysis, drafting, and regulatory intelligence. Application required. - Luminance ($2,000+/month per user): Contract review, analysis, and autopilot. Dominant in M&A due diligence and contract management. - Spellbook ($500-$1,000/month per user): Contract drafting in Microsoft Word. Purpose-built for transactional lawyers. - Everlaw AI ($varies, typically $1,000+/month per user): E-discovery with AI-powered document review. The litigation platform for complex cases. - Relativity aiR ($varies, enterprise pricing): AI integrated into Relativity's e-discovery platform. The standard for large-scale document review.

The recommendation at this tier: Harvey if you can get access and your firm can justify the cost — it's the best legal AI available. Luminance if contract work drives your revenue. Budget $50,000-$150,000/year for enterprise legal AI deployment across a mid-size firm.

The Total Cost of a Legal AI Stack

What does a complete legal AI deployment actually cost?

Solo practitioner: Claude Pro ($20) + existing Westlaw/Lexis = $20/month in new AI costs. ROI break-even: saving 1 billable hour/month.

Small firm (5 lawyers): Claude Pro for all ($100) + CoCounsel for 2 heavy researchers ($400) + Clio Duo for 3 ($375) = $875/month. ROI break-even: saving 3 billable hours/month across the firm.

Mid-size firm (25 lawyers): Harvey for 5 partners ($10,000) + Luminance for 3 transactional lawyers ($6,000) + Claude Pro for everyone ($500) + Clio Duo for associates ($1,500) = $18,000/month. ROI break-even: saving 45 billable hours/month across the firm.

In every scenario, the math works. A single lawyer saving 2 hours/week with AI tools generates $3,000-$4,000/month in recovered capacity at typical billing rates. The tools cost a fraction of that.

The Bottom Line: Start at $20/month with Claude Pro. That's not a consolation prize — it's genuinely the best starting point for any practice size. Add specialized tools only when you've identified a specific workflow bottleneck that general AI can't solve. The firms overspending on legal AI are the ones that bought enterprise tools before understanding their actual needs.