The best AI tools for law firms are Spellbook for drafting, Prudencia.ai and vLex Vincent for case law, and Microsoft Copilot for everyday work, with NotebookLM for case files. I compare them with data from their official sites. To teach your team to use them with judgment, see the Founderz AI master.
Reviewed in October 2026.
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What you’ll take from this
This guide helps you pick a tool by law firm task: case law, drafting, case file synthesis or automating deadlines and notices.
- A comparison of 15 tools with free plan, starting price and availability.
- Which tool fits each task, from case law search to the first draft of a contract.
- A score from 1 to 25 based on official documentation and the plans checked.
- A checklist for confidentiality and data protection, and five steps to bring AI into your workflow.
- Three prompts to start today and answers to the most searched questions.
The best AI tools for law firms: comparison
This table brings together legal AI platforms, general assistants and automation tools, including the ones we teach at Founderz. Data is from each official site in October 2026.
Our rating: how they score
Best for law firms
Spellbook
Contract drafting and review inside Word
Best general assistant
Microsoft Copilot
Daily work in Word, Outlook, Teams
Best free option
NotebookLM
Asking your PDFs and case files questions
How to read this rating
- These tools are very different, so we score within each category: software built for law firms does not compete with a general assistant.
- Fit counts double: a tool built for your sector scores 5; a general assistant that does the job well with good prompts scores 3.
- General assistants (Copilot, ChatGPT, Claude, Gemini) share the same fit score because they do the same kind of job; ease, price, availability and privacy set them apart, and we score privacy for professional use with client data. Ties are broken on privacy.
- Best if you use shows whether a tool works best inside Microsoft 365 or Google Workspace. Copilot and Gemini are not marked down for it, but they are only the best choice if you already work there.
- Scores are based on official information checked on October 25, 2026. This is not a lab test: it is our rating against fixed criteria, and we keep the reason behind every score.
| Software for law firms | ||||||
|---|---|---|---|---|---|---|
| Tool | Fit (×2) | Ease | Value | US availability | Privacy | Total /30 |
| 🏆 SpellbookBest if you use: Microsoft 365 | 5 | 4 | 2 | 4 | 5 | |
| Prudencia.aiBest if you use: Its own platform | 5 | 4 | 4 | 3 | 3 | |
| LegoraBest if you use: Its own platform | 5 | 3 | 1 | 3 | 5 | |
| HarveyBest if you use: Its own platform | 5 | 3 | 1 | 3 | 4 | |
| vLex Vincent AIBest if you use: Its own platform | 5 | 3 | 2 | 4 | 2 | |
| Lefebvre GenIA-LBest if you use: Its own platform | 4 | 3 | 1 | 2 | 2 | |
| General AI assistants | ||||||
|---|---|---|---|---|---|---|
| Tool | Fit (×2) | Ease | Value | US availability | Privacy | Total /30 |
| 🏆 Microsoft CopilotBest if you use: Microsoft 365 | 3 | 5 | 4 | 5 | 5 | |
| GeminiBest if you use: Google Workspace | 3 | 5 | 4 | 5 | 4 | |
| ClaudeBest if you use: Any setup | 3 | 5 | 4 | 5 | 3 | |
| ChatGPTBest if you use: Any setup | 3 | 5 | 3 | 5 | 3 | |
| PerplexityBest if you use: Any setup | 3 | 5 | 3 | 5 | 2 | |
| Automation | ||||||
|---|---|---|---|---|---|---|
| Tool | Fit (×2) | Ease | Value | US availability | Privacy | Total /30 |
| 🏆 Power AutomateBest if you use: Microsoft 365 | 2 | 3 | 4 | 5 | 4 | |
| Copilot StudioBest if you use: Microsoft 365 | 2 | 2 | 3 | 5 | 4 | |
| Productivity and documents | ||||||
|---|---|---|---|---|---|---|
| Tool | Fit (×2) | Ease | Value | US availability | Privacy | Total /30 |
| NotebookLMBest if you use: Google Workspace | 4 | 5 | 5 | 5 | 4 | |
| Other tools | ||||||
|---|---|---|---|---|---|---|
| Tool | Fit (×2) | Ease | Value | US availability | Privacy | Total /30 |
| DeepLBest if you use: Any setup | 3 | 5 | 4 | 5 | 4 | |
How we score: 1 to 5 on each criterion against a fixed scale (fit ×2, total out of 30), from official documentation, plans and prices checked on the date shown. We compare within each category. This is not a lab test.
Each tool in the comparison gets 1 to 5 on five criteria; the total is out of 30.
My pick: Prudencia.ai for case law and filings in Spanish law, because it cites against official sources and publishes plans and prices; and Microsoft Copilot for daily work, because of enterprise data protection and because it lives in Word and Outlook.
Pricing, plans and availability
| Tool | Best for | Free plan | Starting price | US availability |
|---|---|---|---|---|
| Prudencia.ai | Spanish-language legal AI: case law, contracts, filings and procedural deadlines | Yes: 25 interactions | €79/month + VAT (Pro) | Built for Spanish law |
| NotebookLM | Asking your own PDFs and case files with cited answers | Yes | see site | Yes |
| Microsoft Copilot | The firm’s Word, Outlook, Teams and Excel | Copilot Chat free with a work account | €21.84/user/month excl. VAT (monthly) | Yes |
| DeepL | Translation of contracts and documents with glossaries | Yes | €7.49/month (Individual, annual) | Yes |
| Claude | Long document analysis and careful drafting | Yes | $17/month (Pro, annual) or $20 monthly | Yes |
| ChatGPT | First drafts, rewording and client emails | Yes | $20/month (Plus) | Yes |
| Gemini | Google Workspace and quick queries | Yes | €21.99/month (Google AI Pro) | Yes |
| vLex Vincent AI | Spanish legislation and case law search with an AI assistant and citations | 7-day trial | pricing on request | Yes, Spain coverage |
| Perplexity | General search with linked web sources | Yes | see site | Yes |
| Power Automate | Automating deadline notices, forms and flows between apps | 30-day trial | €13/user/month, annual, excl. VAT | Yes |
| Lefebvre GenIA-L | Generative legal AI built on Lefebvre content | Not published | pricing on request | Yes, developed in Spain |
| Spellbook | Contract drafting and review inside Word | 7-day trial | pricing on request | Not confirmed; US-focused |
| Copilot Studio | Your own agent for first client contact over your documents | Trial via a free Azure account | €173.30/month per 25,000 credits | Yes |
| Harvey | Platform for large firms: agents, document vault and research | No; demo | pricing on request | Not confirmed; Spanish clients |
| Legora | Collaborative review, drafting and research, with a Word add-in | No; demo | pricing on request | Not confirmed |
Data checked on October 25, 2026 on each tool’s official website. Prices, plans and terms change often: always check the current details on the provider’s site before you buy.
No affiliates, no sponsorships. Founderz receives no affiliate commission or payment from any of these tools for being listed here. We wrote this guide to give you a genuinely useful resource to help you choose what best fits your needs.
Free plans have usage limits and prices change often; always check the official site.
What they are and who they are for
An AI tool for law firms is a program based on artificial intelligence that assists with searching, analyzing, summarizing and drafting legal documents. It works in natural language: you describe what you need and it returns a result that you review and validate.
There are two families. General AI assistants, such as ChatGPT, Claude or Microsoft Copilot, work for any task, but they do not consult a verified legal source and can hallucinate: cite a ruling that does not exist or attribute an article to the wrong law. Legal AI platforms, such as Prudencia.ai or vLex, connect to legislation and case law databases and link each citation to its source. In both cases, human verification is still required.
The profile that benefits most depends on size. A small firm or solo lawyer saves time on repetitive tasks without hiring. A mid-sized firm standardizes clause review and case law search across several lawyers. A large firm builds AI into departmental workflows, for example in commercial law, with access control and traceability. Nobody needs to code: AI speeds up the mechanical part and leaves billable hours for legal judgment.
Case law: legal AI and search
AI finds rulings from a plain-language description of the case, without mastering Boolean operators. An example: you describe a commercial lease dispute involving a waiver of renewal and ask for the closest rulings, with their reference. Here the verified source makes the difference.
Prudencia.ai
Prudencia.ai is a Spanish-language legal AI based in Barcelona. Its site says it analyzes documents, checks statutes and case law, flags risks and only then drafts, citing against official sources. It includes a procedural deadline and interest calculator. Task: searching rulings for a labor law case and preparing a first filing. Limits: the data guarantees are the company’s own statements; review its privacy policy and data processing terms before uploading case files. Cost: free plan (25 interactions), Pro €79/month and Teams €138/month for 2 users, excl. VAT and no lock-in.
vLex Vincent AI
vLex Vincent AI brings together legislation, case law, forms and commentary from Spain and more than 100 jurisdictions, and its Vincent assistant analyzes documents and answers with citations. Task: uploading the other side’s claim and asking for a list of counterarguments and case law. Limits: I could not confirm official rates; they vary by profile. Cost: pricing on request, with a 7-day trial on vlex.es.
Lefebvre GenIA-L
Lefebvre GenIA-L presents itself as the first generative legal AI solution launched in Europe, developed in Spain and based only on verified Lefebvre content. Task: asking a commercial law question backed by the publisher’s content. Limits: the site publishes no prices, plans or trial. Cost: pricing on request.
Perplexity
Perplexity is an AI search engine that links the web sources behind each answer. Task: cross-checking a regulatory change and opening the sources to verify them. Limits: sources are web pages, not a verified legal database. Cost: free plan; Pro price, see site.
Important
Always verify each ruling against its original source before citing it in a filing. A made-up citation is the responsibility of the lawyer who signs.
Drafting: contracts and filings
AI generates drafts from a description and a set of conditions: a standard contract, a confidentiality clause or a demand letter start from a template the tool adapts. For review, it detects contradictory or missing clauses. You decide which clause best protects the client.
Spellbook
Spellbook is a Word add-in to review, draft and query contracts, with playbooks and benchmarks. It says it is SOC 2 Type II and GDPR compliant and offers zero data retention agreements. Task: reviewing a distribution contract against your clause playbook. Limits: the site does not list languages and its focus is Anglo-American; test it with your contracts before buying. Cost: pricing on request; 7-day trial.
Harvey
Harvey is a platform for large firms and legal departments with agents, a document vault, research and shared workspaces with clients. It lists SOC 2 Type II, ISO 27001 and GDPR. Task: reviewing hundreds of contracts in a due diligence deal. Limits: it publishes no languages or prices and is built for large teams. Cost: pricing on request; demo.
Legora
Legora is a collaborative AI platform to review, research, draft and advise, with a Word add-in. Its site lists ISO 27001, SOC 2 Type II, GDPR and says it does not train on your data. Task: preparing a first draft of a services contract with the team. Limits: it lists no languages or prices. Cost: no published prices; a demo is required.
ChatGPT
ChatGPT works for first drafts, rewording a text or writing the client email. Task: turning your meeting notes into a clear client email, without identifiable data. Limits: it does not consult a legal source and can invent citations. Cost: free plan; Plus $20 a month; Business from $20 per user a month billed annually ($25 monthly).
Claude
Claude handles long documents and careful drafting well. Task: comparing two versions of a contract and listing the changes that affect your client. Limits: it is not a legal database either; verify every citation. Cost: free plan; Pro $17/month billed annually or $20 monthly; Team from $20 per seat.
Microsoft Copilot
Microsoft Copilot works inside Word, Outlook, Teams and Excel, where the firm already keeps its templates and email. Microsoft says that with enterprise data protection, prompts and responses are not used to train the models and stay within the Microsoft 365 service boundary. Task: rewriting a paragraph, comparing versions and summarizing an email thread from a case file. Limits: it is not a legal source. Cost: Copilot Chat free with a work account; Microsoft 365 Copilot €21.84/user/month excl. VAT on monthly billing.
Tip
Start with your own template: give the tool your best anonymized contract as a model and ask it to adapt only the variable parts. The draft then comes out in your firm’s style.
Synthesis: case files and PDFs
Synthesis is where AI pays off most immediately: summarizing an 80-page opinion, extracting the parties’ obligations or locating a clause inside a bulky document. The result is a starting point; the lawyer still reads what matters.
NotebookLM
NotebookLM lets you upload several PDFs and ask questions about them, with answers anchored to the uploaded source. Google states that your data is not used to train the models. Task: loading a matter’s case file and asking which deadlines and obligations appear. Limits: it works only on what you upload and does not replace reading the document. Cost: free plan; paid plans, see site.
Gemini
Gemini fits if the firm works with Google Workspace: it summarizes documents and emails and drafts from Drive and Gmail. Task: summarizing a long expert report into five points. Limits: not a legal source; review the data terms of your plan. Cost: free plan; Google AI Pro €21.99/month.
DeepL
DeepL translates documents with your own glossaries, useful in contracts with a foreign counterparty. For Pro subscribers, its site says data is never used to train its models and cites security certifications. Task: translating a shareholders’ agreement from English with a glossary of legal terms. Limits: the site does not say whether the free plan has the same protection; a legal translation should be reviewed by a professional. Cost: free plan with a monthly limit; Individual price in the table.
Automation: deadlines and notices
Automation connects your tools without coding. In a law firm it shows in three places: first client contact, procedural deadline notices and billing. They are repetitive tasks with clear rules, exactly where the least legal judgment is at stake.
In day-to-day work, AI shows up in a firm’s repetitive tasks: opening a case file, organizing document management, preparing billing from billable hours and answering the client who asks about the status of a matter. Case management software stores the data; AI reads it and prepares the draft email, summary or notice. In commercial, labor or litigation work the workflow is similar: the tool proposes and the lawyer in charge decides. To protect data processing, each firm should decide which documents may go through each tool and put it in writing.
Copilot Studio
Copilot Studio lets you build your own agent over your documents, for example a first-contact chatbot that answers clients asking about fees or required documents. Task: an agent that collects the matter details and sends them to your CRM or to a person in charge. Limits: it needs setup and someone to review its answers. Cost: €173.30/month per 25,000 credits; trial with a free Azure account.
Power Automate
Power Automate links apps and builds flows. Task: having each deadline noted in the case file trigger a notice in Outlook and Teams to the lawyer in charge, with earlier reminders. Limits: AI does not compute the deadline for you; you enter it and check the count. Cost: €13/user/month billed annually, excl. VAT; 30-day trial.
Use cases: legal practice with AI
This is a practical guide for lawyers and firms that want to use AI in legal practice without losing judgment. The most common use cases of AI tools for lawyers are searching legal knowledge in a database, drafting repetitive documents and tracking cases. Artificial intelligence applied to law does not change the way of working overnight: it cuts the mechanical workload and leaves more time for legal professionals.
AI solutions split into general AI systems and sector platforms based on AI, and the AI models behind them are trained on large datasets. How each one works with legal context depends on the product: some read the case file data and the client data you provide; others only query their own database. To speed up case management with efficiency and accuracy, always ask which internal information each tool uses and which stays out. How to implement a customer service chatbot or a drafting assistant depends on your specific needs, and the less manual intervention you want, the more review you need at the end. AI never replaces legal judgment.
With confidential information, using AI in a firm requires clear rules: which client documents may be uploaded, who authorizes it and how they are anonymized. The frequently asked questions below answer the most common doubts about artificial intelligence for lawyers and law firms.
How to choose the right tool
Before buying, go through this list with whoever handles data protection at the firm:
- Confidentiality and GDPR: is your data used for training? Where is it hosted? Is there a data processing agreement?
- Legal source: does it cite rulings and statutes with a link to the official source?
- Integrations: Word, Outlook, your case management software and your CRM.
- Cost per user: compare the per-seat plan with the billable hours you recover.
- Spanish and Spanish law: test it with a real, anonymized case.
- Learning curve: how long the team takes to use it unaided.
How to bring AI into your workflow
Integration works best in small phases. Start with what is repetitive and low risk, not the most delicate case.
- Identify a repetitive task. Summarizing opinions, drafting standard clauses or searching case law.
- Choose by data sensitivity. Without personal data a general assistant is enough; for confidential documents, an environment with contractual guarantees.
- Run a pilot case. Test the tool on a controlled matter and measure the time you recover.
- Always review the output. Nothing goes to the client without the lawyer’s validation.
- Standardize what works. Turn the uses that work into a procedure for the whole team.
Training for your team
Picking the tool is the easy part; getting the whole team to use it well, with data protected, is harder. Founderz teaches a method that works with Copilot, ChatGPT, Claude, Gemini and the specialist tools for law firms.
Important
Do not enter client personal data or privileged information into free versions of general AI whose data handling you do not control. Use business plans with contractual guarantees or anonymize first. Professional responsibility stays with the lawyer who signs.
Free tool
Legal drafting prompt generator
Pick your case, adjust the options and get a complete prompt ready to paste into ChatGPT, Copilot, Claude or Gemini.
Open the generatorPrompts to get started
Three prompts to copy and paste. What goes in brackets is your case; do not paste identifiable data. For more, see the AI prompts for lawyers.
Summarize this ruling in at most 200 words for a lawyer: parties, relevant facts, legal issue, holding and main reasoning. Flag any information not in the text instead of assuming it. Text: [paste the anonymized ruling]Act as a commercial lawyer. Draft a first version of a confidentiality clause for a services agreement between [company A] and [company B], lasting [X] years. Use clear language, list the assumptions you made and mark the points I must review.Compare these two versions of a contract and show in a table the clauses that changed: number, old text, new text and risk for my client ([party]). Version 1: [paste]. Version 2: [paste].Frequently asked questions
These are the questions searched most when a law firm starts using AI.
Which AI is recommended for lawyers?
It depends on the task. For case law and Spanish law, a legal platform such as Prudencia.ai or vLex; for daily work, Microsoft Copilot, Claude or ChatGPT. Combine both by data sensitivity and always verify the result.
What is the best AI for lawyers?
There is no single one. In my scoring, Prudencia.ai fits best for research and drafting in Spanish law, and Microsoft Copilot for daily work with enterprise data protection. The best is the one that covers your task with the data guarantees you need.
Is there a free AI for lawyers?
Yes, with limits. Prudencia.ai has a free plan of 25 interactions, and ChatGPT, Claude, Gemini, NotebookLM and DeepL have free plans. Do not upload confidential data to a free plan without checking its terms.
How much does AI cost for a law firm?
From €0 on free plans to tens of euros per user per month: Prudencia.ai Pro costs €79/month and Microsoft 365 Copilot €21.84/user/month excl. VAT. Harvey, Legora, vLex and Lefebvre do not publish prices.
Do ChatGPT and Copilot work for searching Spanish case law?
With caution. They do not consult a verified legal source and can invent rulings. For case law, a platform connected to legal databases is more reliable; if you use a general assistant, check every citation at the original source.
Is AI safe for confidential legal documents?
It depends on the plan. Use business environments with contractual guarantees and GDPR compliance, anonymize when you can and keep human oversight. Each vendor’s claims should be checked against its privacy policy.
Can AI replace the lawyer?
No. AI speeds up research, synthesis and drafts, but strategy, interpretation and professional responsibility stay with the lawyer.
The tools we teach at Founderz
In the Founderz program you can take, you work through practical cases with these tools:
Your next step
Pick one task that repeats every week in your firm, test it with a tool from this guide and measure the time recovered. If you want your team to apply AI with judgment and respect confidentiality, the Founderz AI program, from a school with Microsoft as Worldwide Training Partner, gives you the method to do it without losing control.
This article is informational and educational and is not legal advice. Processing of client data is governed by Regulation (EU) 2016/679 (GDPR).