LEO
LEO is a Dutch legal AI assistant from PrudAI for law firms and in-house counsel. It analyses case files, researches case law and drafts documents, verifying every citation word for word against 102 official sources.
What is LEO?
LEO is a legal AI assistant built for Dutch legal practice by PrudAI, a company based in Enschede. The name is a play on the Latin Lex Explanata Oraculo, and leo also simply means lion. The product was previously called ALEX, and the former address still redirects to the current one. It is one of five sector assistants from the same publisher, alongside VERA for construction, ZIA for healthcare, BEVER for public decision-making and IRMA for compliance.
Rather than a single chatbot, LEO runs a team of specialised agents that the user can watch working: a researcher, an analyst, a writer and an auditor, plus a separate calculation agent. That last one matters, because numerical questions such as child maintenance under the Trema standards, spousal maintenance, statutory interest, VAT, indexation and deadline calculations are handled step by step rather than by the language model. The auditor checks every citation from the writer word for word against the source, and if it finds no exact match the whole answer is blocked before the user ever sees it.
The knowledge base is what the vendor leans on hardest: 102 official Dutch and European sources covering roughly 8.4 million searchable documents. Beyond legislation and case law, it reaches layers competitors tend to skip, including regulators such as the data protection, competition, healthcare and employee insurance authorities, complaints and dispute bodies, and registers including the chamber of commerce and the buildings register. Fifty-four curated professional corpora sit on top, and thirty-six practice areas can be configured individually.
LEO handles volume as well as depth: an example on the site processes 608 employment contracts in one run into a sortable table where every cell traces back to its contract. It works inside the tools firms already use through a Word add-in, an Outlook add-in and SharePoint, with Microsoft single sign-on. Delivery is a web application plus those Office add-ins; there is no mobile app and no public API.
What it does
- Ask a legal question in plain Dutch, with no search syntax or prompt training
- Analyse a complete case file and surface the case law that bears on it
- Open any citation directly on the exact passage the answer rests on
- Build a document table across hundreds of contracts in a single run
- Draft a defence or memo inside Microsoft Word as tracked suggestions
- Run statutory calculations through a dedicated calculation agent
- Assemble a case chronology automatically from the underlying documents
When to use LEO / When not to
A quick filter to help you decide if LEO is the right fit.
When to use LEO
- Dutch law firms handling voluminous case files and litigation work
- In-house counsel and corporate legal teams operating under Dutch law
- Insolvency trustees who need to grasp a bankruptcy estate quickly
- Tax specialists and tax advisers, through the dedicated LEO Fiscaal variant
- Legal teams already working inside Microsoft Word, Outlook and SharePoint
When not to use LEO
- Lawyers practising outside Dutch and European law, for which coverage is minimal
- Solo practitioners with occasional needs, given the single plan at EUR 179 per month
- Developers looking for a public API or self-service integration keys
- Anyone who needs a permanent free tier rather than a 14-day trial
- Users who want a mobile app, since LEO is web plus Office add-ins only
How to use LEO
A typical end-to-end flow, from setup to results.
- Start the 14-day trial with just a name, an email address and a company name
- Activate the account from the confirmation email and sign in at the web application
- Sign in with Microsoft single sign-on where the firm has it configured
- Choose your role, from advocate and in-house counsel to notary, tax specialist or mediator
- Set your practice area so LEO loads the matching sources and specialised agent
- Refine the source selector by jurisdiction and source type if needed
- Drop the case documents in and let classification, chronology and tasks build themselves
- Ask your question in plain Dutch and read which sources were used beneath the answer
- Click any reference to open the source document on the exact passage
- Export to PDF or Word, or accept the suggested edits through the Word add-in
Pros & Cons
Pros
- Citations are verified word for word by a separate agent and open on the exact passage
- Source coverage includes regulators, dispute bodies and registers that rival suites omit
- No training on customer data, committed both contractually and technically
- Customer documents stay on the vendor's own EU servers rather than a hyperscaler
- Subprocessors are published by name with their role and processing region
- Pricing is public and the 14-day trial needs no credit card
- It works inside Word, Outlook and SharePoint instead of adding another environment
Cons
- ISO 27001 and NEN 7510 are audited but not yet certified, with certificates only expected in Q4 2026
- Coverage is effectively confined to Dutch law, with almost nothing outside it
- No permanent free plan and a single paid tier, so no cheap entry point
- No public API and no self-service keys: every integration goes through an account manager
- No mobile application, and the interface and documentation lead in Dutch
- No dedicated support address is published; support runs via form, docs or account manager
- The publisher is very young and very small, with the operating entity registered in 2026
Pricing & Plans
There is no permanent free plan. LEO offers a 14-day free trial that requires no credit card, after which access stops automatically unless a payment method is added. A single paid tier, LEO Professional, is offered at EUR 179 per month billed monthly, or at EUR 149 per month on an annual commitment invoiced as EUR 1,788 per year. The lowest price point is therefore EUR 149 per month, available only with annual billing.
- in-depth case file and case law analysis
- graphical and structured analyses
- extensive legal and tax source library
- SharePoint integration for firm-wide files
- LEO Professional (annual) — EUR 149 per month
- invoiced as EUR 1
- 788 per year and marked as the most chosen option
- identical contents
- presented as two months free against monthly billing
Data, GDPR & hosting
A consolidated view of how LEO handles your data.
GDPR overview
GDPR compliance is stated explicitly: the trust centre lists GDPR as compliant and the privacy statement is built around the AVG. PrudAI documents its dual role of controller and processor, and publishes a Data Pro Statement, a full processing agreement aligned with NLdigital 2025, covering breach notification within 48 hours, an audit right and a chain of responsibility down to subprocessors. Data subjects can request access, rectification, portability and erasure via privacy@prudai.com. All processing is said to remain physically and contractually inside the European Union. Note that the control framework is aligned to ISO/IEC 27001:2022 and NEN 7510 but is not yet certified: the audit closed in August 2026 and certificates are only expected in Q4 2026.
Who owns the data?
The customer remains the owner of their data: the security page states plainly that you stay the owner, and processing arrangements are a standard part of the contract. PrudAI splits its roles under the GDPR. When a firm uses the SaaS application to analyse documents and generate text, PrudAI acts solely as a processor on behalf of the client organisation, which is the controller. PrudAI is controller only for its website, marketing, sales conversations, account and subscription data. A processing agreement aligned with the NLdigital 2025 terms governs the relationship, each firm works in a private tenant, and data is never shared with other PrudAI customers.
Reuse rights
Customers may export their documents and generated results at any time during the contract, in a common machine-readable format, without asking permission. PrudAI uses data only to deliver the service: account and contact details to grant access, billing data handled through Stripe, and the prompts, documents and metadata submitted through the application together with the generated output. The vendor commits both contractually and technically that prompts and completions are never used to train, improve or fine-tune any AI model, whether its own or a subprocessor's. Zero data retention with in-memory processing means model providers keep nothing after the response, and human review by staff or suppliers is technically excluded.
Data retention & training
Hosting summary
Client documents and case data are stored on PrudAI's own servers in EU data centres, at Hetzner sites in Nuremberg and Falkenstein in Germany and Helsinki in Finland, and the vendor stresses that no hyperscaler is used for this storage. AI inference runs through EU endpoints: Microsoft Azure OpenAI in Sweden Central and Google Vertex AI in EU regions, both with contractually agreed zero data retention, plus Nebius in Finland and France for open-weights models and DeepL in Germany for optional translation. Vercel hosts the web front ends from the Frankfurt edge and handles no documents, prompts or case data. Traffic is encrypted with TLS 1.2 or higher, and production hosts run from a fully encrypted LUKS2 volume that also holds the backups. Subprocessors are reviewed annually, with standard contractual clauses where a provider does not fix its region contractually. Note that the site's public IP geolocates to the United States, but that is an anycast CDN node and says nothing about where data lives.
Things to keep in mind
Risks and trade-offs to weigh before adopting LEO.
- ISO 27001 and NEN 7510 are advertised as expected in Q4 2026, not held: do not read the badges as certifications
- The site's own llms.txt describes the stack as Azure Sweden Central plus Vertex US-DPF, which sits awkwardly with the claim that no data leaves the EU
- The comparison table is written by the vendor and rates unnamed competitors, so it is marketing rather than a neutral benchmark
- The savings figures rest on the vendor's own assumptions, which it displays but which remain assumptions
- The publisher's about page says founded in 2025, while the registered entity behind the KVK number dates from February 2026
- A citation checker reduces but does not remove the risk of over-reliance: professional responsibility for the advice stays with the lawyer
- Feeding privileged client material into any assistant concentrates confidentiality risk in one supplier, here a very small and very new one
Setup & Integrations
Technical difficulty
Very low for the individual user: you sign up with a name, email and company name, receive an activation email and can start straight away, with no search syntax or prompt training to learn and a built-in onboarding tour. The vendor claims most users produce a usable answer within ten minutes. Firm-wide deployment asks more of an administrator, who configures Microsoft single sign-on and the SharePoint connection and rolls out the Word and Outlook add-ins. Custom links to a document management system or CRM are not self-service and are arranged with an account manager.
Deployment
Integrations
Supported languages
Behind LEO
Social
Resources
All the official URLs gathered for verification and reference.
Alternatives
Tools that compete with or complement LEO.
Frequently asked questions
What does the name LEO stand for?
Is my client data used to train the AI models?
Where is my data stored?
How reliable are the answers?
Can it handle numerical questions such as maintenance calculations?
Does LEO work with the systems we already use?
Is there a free trial, and do I need a credit card?
Does LEO offer a public API?
Is LEO certified to ISO 27001?
Which sources does LEO actually read?
Should you pick LEO?
LEO is a deliberately narrow product, and that is its strength. Instead of competing with general assistants on breadth, PrudAI has built for one jurisdiction and gone deep: 102 official Dutch and European sources, thirty-six configurable practice areas, and layers such as regulators, dispute bodies and public registers that broader international suites tend not to open up. For a practitioner working in Dutch law, that focus is worth more than a longer feature list.
The most convincing part is the treatment of citations. A separate auditor agent checks every quote word for word against its source and blocks the whole answer when it cannot find an exact match, and references open on the passage rather than the document. Routing numerical work to a dedicated calculation agent follows the same logic. Taken together, these are the design choices of a vendor that expects its output to be relied on in court.
The privacy posture is unusually concrete: no training on customer data, storage on the vendor's own EU servers, named subprocessors, and a published processing agreement with a 48-hour breach window and an audit right.
Two caveats deserve weight. The ISO 27001 and NEN 7510 certificates are expected, not held, so LEO should not be presented as certified before Q4 2026. And the publisher is very young: the operating entity was registered in February 2026 and the register shows a single employee, which is a real consideration when entrusting a firm's most confidential material to a supplier.
At EUR 149 to 179 per month with a single tier, LEO is priced for firms rather than individuals. The 14-day trial without a credit card is the sensible way to judge it, and the vendor's own framing, roughly one billable hour per month, is a fair test to apply.
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