Legartis vs ThoughtRiver: how they compare in 2026

L
Legartis profile
T
ThoughtRiver profile
Last verifiedSeptember 25, 2026
Verdict

Legartis and ThoughtRiver are both European AI contract review tools for in house legal teams. Both score contracts against a customer's playbook and propose redlines in Word. Both give customer contracts a role in model training. ThoughtRiver's data processing addendum lists machine learning training and feature enhancement among its purposes. Legartis offers an opt out of model training only on its Team and Enterprise plans. Legartis leads on control and price. It shows a quality score for each playbook requirement, lets users correct the system in test sets, and keeps a human as the final checkpoint. It publishes prices, from a free tier to CHF 3,000 per user a year for Team, with Enterprise quoted. ThoughtRiver's counterweight is data handling and measurement. It publishes a subprocessor list, per customer encryption keys and breach notice, and an accuracy of 97.3 percent across its question set.

Which one fits

Choose Legartis if

  • You want to see how reliable the review is for each requirement. Legartis shows an AI Quality Score per playbook requirement, lets your team correct how the system read a requirement inside test sets, and flags clauses outside expected patterns even where the playbook is silent.
  • You want to price it without a call. Legartis's plans page lists a free tier for two NDAs a month and Professional at CHF 2,500 per user a year for 120 contracts. Team costs CHF 3,000 for 250 contracts, and Enterprise terms are custom.
  • You work across European languages and want data in Switzerland. Legartis supports every European language on paid plans, hosts in Switzerland and Europe with data on Zurich servers, offers a Word add in, a REST API and an MCP integration, and states ISO 27001.

Choose ThoughtRiver if

  • You want a measured accuracy claim and a named customer figure. ThoughtRiver states 97.3 percent accuracy across its 2,500 pretrained questions, and a Shoosmiths partner reports supply agreements reviewed in under three minutes at above 90 percent accuracy, against four hours at 86 percent by qualified lawyers.
  • You need data handling commitments in a published addendum. ThoughtRiver's data processing addendum names five subprocessors with locations, commits to breach notice without undue delay and to deletion or return on termination, and each customer's data is encrypted under its own key in a UK Azure region.
  • You want every issue in a contract on one list. ThoughtRiver's Digital Issues List rates the risk of every point to resolve against your playbook, tracks resolution status, can be downloaded as a PDF, and pairs with suggested redlines in Word and portfolio analysis.

At a glance

Category
LegartisContract Review & Drafting
ThoughtRiverContract Review & Drafting
Founded
Legartis2017
ThoughtRiverNot published
Headquarters
LegartisZurich, Switzerland
ThoughtRiverCambridge, England, United Kingdom
Last verified
LegartisOct 8, 2026
ThoughtRiverSep 6, 2026

All 15 axes, side by side

The same grid applied to every vendor in the index, graded from public sources. Hover a grade to see what the letter means on that axis.

AI Centrality

How much of the product is actually AI. Whether the machine learning is the mechanism the buyer is paying for or a feature layered onto conventional software, and whether the vendor is specific about which is which.

Legartis
AA on AI CentralityThe artificial intelligence is the product. Remove the models and there is nothing left to sell.

Legartis sells the product as a Legal AI Workspace built on an agentic framework. Its named components are the Review Agent, the Legal Agent and the Playbook Creator Agent, and every capability a customer pays for runs through these agents. Since agentic workflows launched on 23 September 2026, the Legal Agent takes on complete legal processes, from incoming requests and contract review to negotiation, approvals, reporting and signature. The pricing page also lists e signature via DocuSign and a contract repository with status and versions. Workflows can be created by voice or in writing and reused across the workspace. Procurement and sales teams work in their own Focus Spaces, under rules and templates legal has approved.

ThoughtRiver
AA on AI CentralityThe artificial intelligence is the product. Remove the models and there is nothing left to sell.

Machine learning is the mechanism the customer pays for. A model reads the contract, answers the Lexible question set, scores the answers against a playbook and produces the risk rating, issues list and suggested redlines. Remove the models and there is no review, no issues list and no redlines, only a document store. The vendor has sold this as an AI product since 2016 and describes the current engine as a proprietary generative model on several large language models.

Citation Accuracy and Hallucination Disclosure

Whether the vendor publishes measured accuracy on citations and assertions, grounds output to primary sources, and says plainly what its system does when it does not know. Legal has a documented public record of fabricated citations reaching filed briefs, so an untested claim of accuracy is not evidence.

Legartis
BB on Citation Accuracy and Hallucination DisclosureGrounding is real and documented, with linked primary sources and a described retrieval method, short of published accuracy figures an outsider can test.

Legal experts define the playbook requirements against which Legartis evaluates contracts. Each requirement has a reliability indicator derived from test examples, and users can correct classifications to tune future reviews. The interface traces review results to a requirement and contract passage; legal questions carry citations to supporting sources. The quality framework names inaccurate instructions, missing context, interpretation differences and invented information as distinct failure modes. Customer dashboards expose performance within their own workflows, but a reproducible public test set and current accuracy results are not provided. The widely stated reduction in review time measures speed rather than legal accuracy.

ThoughtRiver
BB on Citation Accuracy and Hallucination DisclosureGrounding is real and documented, with linked primary sources and a described retrieval method, short of published accuracy figures an outsider can test.

Lexible uses lawyer labeled concepts to identify contract provisions and assess them against a playbook. Its accuracy explanation reports 97% F1, 96% precision and 97% recall, with testing three times weekly against 750,000 verified data points. Legal specialists verify training examples, and sampling covers different contract types and domains. These figures concern classification and do not measure every generated redline or answer. The underlying dataset, current model version and detailed failure results are not available for independent reproduction. The terms acknowledge that training can reduce accuracy, especially with incorrect labels, and that mistakes remain possible.

Autonomy and Oversight Model

What the system decides on its own, what a lawyer must approve, and whether the vendor documents where the review point sits. A tool that drafts under review and a tool that files without one are different products and different risks.

Legartis
AA on Autonomy and Oversight ModelWhat the system runs alone, what constrains it, and how a lawyer checks it are all published: modes, thresholds, review surfaces, and the route a matter takes back to human judgment. A categorical limit on a named mode or tier, stating what its output may not be used for, meets the threshold limb without a number.

The system works against legally validated requirements and company playbooks, and legal experts rather than the model define what counts as correct. Legartis names four review tools. AI Quality Scores for each requirement appear in a dashboard, and in test sets the user reviews and corrects how the system understood a requirement. Detection of clauses outside expected patterns and a full audit trail complete the set. It states twice that judgment returns to a person. A human is the final checkpoint before any decision is made on an AI classification, and accountability stays with the organization, not the AI, when agents draft, review or flag clauses. The path for a misclassification is documented end to end, from detection through correction in the test set to the system applying that correction to similar cases. Since the agentic workflows launched on 23 September 2026, legal teams set the playbooks, templates, responsibilities and decision boundaries the Legal Agent follows. When a deviation exceeds a boundary, such as a liability clause outside the agreed position, the agent refers it to the responsible person for a decision. Legartis publishes no default boundary, and each customer sets its own.

ThoughtRiver
BB on Autonomy and Oversight ModelA written commitment that the models work alongside a supervising lawyer, with real review surfaces, short of the full control structure: commonly the threshold at which the system stops or what happens after it is wrong.

The platform reads an agreement, identifies issues against a configured playbook and presents suggested redlines in Word. Users can share issues and changes with colleagues, while Lexible Assistant supports questions and remediation. The customer sets its risk policies and remains responsible for decisions based on the resulting analysis, including automated decisions. Terms expressly warn that output is not legal advice and may contain mistakes. These features provide a review surface and organizational standards. The system does not specify when it can approve an agreement without review or how it must escalate and correct an incorrect conclusion.

Operational and Outcome Evidence

Named, dated evidence that the product works in production at real firms or legal departments. Case studies with figures and identified customers count. Unattributed testimonials and launch announcements do not.

Legartis
BB on Operational and Outcome EvidenceReal deployment evidence with substance, short of full attribution or measurement: a named customer without figures, or figures without the named customer.

Two customers, dormakaba and TUEV NORD, have dedicated case study pages. Seven more appear as logos (Uniklinik, Emmi, Fiege, Oechsler, Framatome, Zuercher Kantonalbank and Arabelle Solutions). Legartis cites a DPA first review falling from 45 to 60 minutes to under 10, and contract review up to 85 percent faster. It also cites playbook creation effort down up to 98 percent and costs down more than 90 percent on portfolio risk analysis. Testimonials carry personal names, including Kim Weiler, Dr Marc Hansmann, Cedric Ruepp, Gordian Berger and Juerg Sommer. The testimonials do not give these individuals' organizations, so the figures they quote are not tied to a named customer.

ThoughtRiver
BB on Operational and Outcome EvidenceReal deployment evidence with substance, short of full attribution or measurement: a named customer without figures, or figures without the named customer.

A named customer gives figures, without a date or method. Joe Stephenson, partner and head of technology at Shoosmiths, is quoted on the demo page saying the platform reviewed complex supply agreements in under three minutes at above ninety percent accuracy, where lawyers took four hours at 86 percent. A second, unnamed customer calls ThoughtRiver a clear winner for reviewing its appointments. No date, sample size or method accompanies the Shoosmiths figures.

Privilege and Confidentiality Posture

How client confidences are handled: attorney client privilege and work product treatment, segregation of one client matter from another, whether client data trains any model, and what the vendor commits to in writing rather than in marketing.

Legartis
CC on Privilege and Confidentiality PostureConfidentiality is asserted in general terms, or the commitment lives only in a sales conversation and cannot be read in advance.

The home page and pricing page state no data sharing with third parties, GDPR compliance, ISO 27001 certification and hosting in Switzerland and Europe. The pricing page uses the narrower phrase no uncontrolled data sharing. The only published data document is a privacy policy last updated 6 November 2019. It addresses website and account data and does not address uploaded contracts, prompts or outputs. On training, the only published statements are on the pricing pages, which offer exclusion of the customer's data from model training on the paid Team to Enterprise plan only. Legartis does not address segregation between customers or between matters, states no retention or deletion position for contract content, and identifies no model provider. Nothing on its site mentions privilege, professional secrecy or work product.

ThoughtRiver
BB on Privilege and Confidentiality PostureSubstantive published commitments on confidentiality and training use, short of the full picture: commonly silence on segregation between users or matters, or on what the underlying model provider may retain.

The agreement treats customer contract data as confidential and restricts disclosure by staff and subcontractors, with confidentiality continuing after termination. Customer accounts have separate encryption keys and segregated contract data. Anonymization removes sensitive information before model processing. The same agreement grants continuing use of training data and anonymized contract text, and the DPA includes machine learning training among processing purposes. This is permission to reuse specified material, rather than a promise never to train. The terms do not cover internal matter walls or privilege handling directly, and ThoughtRiver gives no complete account of the underlying language model providers.

UPL and Professional Responsibility Posture

Whether the vendor is clear that it supplies a tool rather than legal advice, who its audience is, and how it addresses unauthorized practice of law, competence and supervision duties, and jurisdiction limits. ABA Formal Opinion 512 is the reference point. Where the advice line is not the duty a product raises, the axis is read through the nearest professional duty it does raise: judicial conduct rules and the reviewing duty for products sold only to courts, and the duty to bill for time actually spent for products that draft time entries.

Legartis
BB on UPL and Professional Responsibility PostureA real position is published on advice versus tooling, short of full treatment: commonly a disclaimer without the supervision and competence dimension, or silence on jurisdiction limits.

Asked in its FAQ who is liable if the AI makes a mistake, Legartis answers that when a lawyer sends a signed document it makes no difference how it was created. The lawyer remains liable, the AI is an assistive tool, and legal responsibility stays with the person who approves the result. A companion answer says accountability stays with the organization rather than the AI. Both positions sit in FAQ prose rather than in an agreement. No jurisdiction limit is stated, although the product is sold across every European language and legal system. Legartis also invites people who are not lawyers to work in the product. A dedicated FAQ confirms that procurement and sales teams review contracts on their own in line with legal standards. No statement on scope of use for those users is published.

ThoughtRiver
BB on UPL and Professional Responsibility PostureA real position is published on advice versus tooling, short of full treatment: commonly a disclaimer without the supervision and competence dimension, or silence on jurisdiction limits.

The customer terms expressly say that output is not legal advice and must not be relied on as advice. They also warn that predictive technology makes mistakes and that incorrect training can worsen accuracy. Customers remain responsible for results, conclusions and automated or manual decisions. The license allows both internal business work and integrated managed services for legal clients, so law firms and other business users share that responsibility. Product review surfaces support human checking, but jurisdiction specific practice limits and an explicit treatment of lawyers' competence and supervision duties are not set out.

AI Governance and Bias Disclosure

Published governance over model behavior: who owns it inside the vendor, what is tested before release, and what is disclosed about disparate output across matter types, parties, or populations.

Legartis
BB on AI Governance and Bias DisclosureA published governance framework with real substance, short of testing results or a named owner.

The AI Quality System comes in three named layers, each with a described mechanism. Playbooks and Legal Best Practices with Agent Memory form the knowledge base, AI Quality Scores come with feedback loops and targeted user tuning, and clauses outside expected patterns are detected. Three published articles cover auditable AI, explainable AI and governing agentic legal AI. Legartis distinguishes explainable AI, which shows how a decision was reached, from auditable AI, which checks whether output meets a defined standard. Nobody inside Legartis is named as accountable for AI governance, no testing regime before release is described, and no testing results are published. Nothing is published about uneven output across matter types or populations, although bias appears in a section heading. ISO 27001 is a security management standard and does not cover AI governance.

ThoughtRiver
BB on AI Governance and Bias DisclosureA published governance framework with real substance, short of testing results or a named owner.

ThoughtRiver describes lawyer verification of training examples, annotation that accounts for contract context and sampling across contract types and legal domains. Its evaluation program runs three times each week against 750,000 verified data points and reports separate precision, recall and F1 measures. Customers can set playbooks for their own risks and review proposed changes before further use. These are concrete training and evaluation practices. The description does not identify an accountable AI governance owner, a mandatory release approval threshold or findings about uneven output across jurisdictions or populations. Its regulatory position is separate from those operating tests.

AI Safety and Data Stewardship

Retention, deletion, access control, and what happens to prompts and documents after they are processed. Whether the vendor states its subprocessors and its incident practice, or leaves the buyer to assume.

Legartis
CC on AI Safety and Data StewardshipA generic privacy policy covers the product without addressing what happens to documents and prompts after processing.

Data handling is governed by a privacy policy last updated 6 November 2019. It covers website and account data and does not address what happens to uploaded contracts, prompts or generated output after processing. Its retention section speaks generally, saying aggregated, anonymized or pseudonymized information may be kept indefinitely, and states no retention period for contract content. No deletion position or incident and breach practice is published. The policy names Turicode, VSHN and LinuxFabrik as third party processors for Application users. All three are Swiss infrastructure and operations suppliers, and no AI model provider is among them. Access control appears only as paid features in the pricing matrix, with role management, document controls and audit logs on the paid Team to Enterprise plan. Personal data is stated to be stored on servers in Zurich.

ThoughtRiver
BB on AI Safety and Data StewardshipSubstantive published policy covering most of the ground, short of the full set: commonly no named subprocessor list or no stated incident practice.

The DPA names infrastructure, authentication, document conversion, email and support providers, and requires equivalent safeguards for subprocessors. Personal data breaches must be reported without undue delay, with cooperation in mitigation. Customer data is encrypted in transit and at rest, separated by account and protected by a dedicated encryption key. Authentication supports single sign on and multifactor controls. At termination, personal data must be deleted or returned, with backup and legal exceptions. ThoughtRiver gives no in use retention period for prompts, no backup deletion deadline and no explicit list of the language models processing contract text.

AI Liability and Recourse

What the vendor stands behind contractually when its output is wrong. Indemnities, caps, carve outs, insurance, and whether any of it is published or only reachable through a negotiated agreement.

Legartis
DD on AI Liability and RecourseNothing published on who bears the loss when the system is wrong.

The legal section of the site footer offers two documents, a legal notice and a privacy policy, and neither is a contract for the service. Legartis publishes no customer agreement. The legal notice is a website disclaimer. It disclaims the accuracy of information on the website, excludes liability for losses from using that information, and puts reliance at the user's own risk. It governs the website rather than the Application. No indemnity, liability cap, warranty on the service or its output, or insurance position is published. On who bears the loss, the only statement is an FAQ answer on the AI Quality System page. It says the lawyer who signs remains liable and accountability stays with the organization. That answer is marketing prose that puts risk on the customer, and it is not a contractual term binding Legartis.

ThoughtRiver
BB on AI Liability and RecourseA real published position on liability, short of the full picture: commonly a stated indemnity without scope or caps.

ThoughtRiver indemnifies customers against claims that permitted use of the platform infringes third party copyright, subject to control of the defense and exclusions for unapproved combinations. It can replace or modify the platform to address infringement. General liability is limited to the order term's fees, or £1,000 during a trial, with the copyright indemnity excluded from that cap. Death or injury caused by negligence, fraud and other legally unavoidable liabilities also remain outside the limitation. Output errors carry no warranty or accepted liability, so the software indemnity does not amount to a guarantee of correct legal analysis.

Practice Systems Integration Depth

How deeply the product reaches into the systems legal work already lives in: document management such as iManage and NetDocuments, Word and Outlook, contract lifecycle management, matter management, e-billing, and court filing systems.

Legartis
BB on Practice Systems Integration DepthReal integrations exist and are documented, short of depth: named connections without a description of what they actually move.

The Word add in is the main integration, and customers on Microsoft Office 2019 or Office 365 can install the Legartis Word app. An open REST API is described as letting Legartis run as a standalone web app alongside any contract management solution. The pricing matrix lists API and MCP integrations on the paid Team to Enterprise plan. Legartis has no integrations page or developer documentation, and does not describe what moves between systems or in which direction. The pricing page now lists e signature via DocuSign, and the Team to Enterprise plan adds SSO.

ThoughtRiver
BB on Practice Systems Integration DepthReal integrations exist and are documented, short of depth: named connections without a description of what they actually move.

Agreements enter through email, file upload or a Microsoft Word add in, with issues and redlines available for team collaboration. Microsoft 365 supports work in Word, Outlook and Teams, while Power BI receives contract data for analysis. HighQ and iManage are named connections for legal projects and document workflows. The platform also exposes the same public APIs used by its web application and follows the OpenAPI specification. These connections have identifiable purposes, but per connector field mappings, authentication setup, permission inheritance and error recovery steps are not described in the integration overview.

Deployment Model and Data Residency

Where the software runs and where the data sits. Multi tenant cloud, single tenant, private deployment, on premises, and whether region of residence is a published option or an enterprise conversation.

Legartis
BB on Deployment Model and Data ResidencyDeployment model is stated clearly with partial residency detail, or residency is offered without the processing location being addressed, or the tenancy model is stated on its own with no residency detail published.

Hosting is in Switzerland and Europe, according to the product and pricing pages, and the arrangement is the same on every tier. The privacy policy says personal data is stored on servers in Zurich. Processing location is not addressed separately from storage. No model provider is named, which leaves the inference location open. Legartis does not say whether the platform is single tenant or multitenant, or how customers are separated. The only related detail is document level permissions, offered as an Enterprise feature. No deployment option varies the hosting arrangement.

ThoughtRiver
BB on Deployment Model and Data ResidencyDeployment model is stated clearly with partial residency detail, or residency is offered without the processing location being addressed, or the tenancy model is stated on its own with no residency detail published.

Region and processing location are stated, and tenancy is described as segregation. The security page says data resides in Azure data centers managed and secured by ThoughtRiver in a single specified region, and the subprocessor table places Azure hosting in the United Kingdom. Each customer's data is held separately under its own key. ThoughtRiver does not say whether a customer may choose a region other than the UK or whether infrastructure is shared, and it does not address where the language models run inference.

Security Certifications and Trust Center

Independent attestation a buyer can pull without a sales call: SOC 2, ISO 27001, penetration test summaries, a trust center with current reports and named scope rather than a badge image.

Legartis
BB on Security Certifications and Trust CenterCertification is real and stated, short of accessible evidence: a named standard without scope, date, or a way to obtain the report.

An ISO 27001 certification is claimed. The claim appears in the home page trust block, the security section of the AI Quality System page, the pricing matrix and a badge in the site footer. No certifying body, certificate number, scope statement or statement of applicability, or issue or expiry date is published. Legartis has no trust center or portal, and offers no route to obtain a report at any access tier. With no certifying body named, the claim cannot be matched to a register without contacting Legartis. No penetration testing is mentioned.

ThoughtRiver
BB on Security Certifications and Trust CenterCertification is real and stated, short of accessible evidence: a named standard without scope, date, or a way to obtain the report.

ISO 27001 certification is stated and identified by number, without a route to the report. The security page gives certificate number 21188-ISMS-001 alongside encryption at rest and in transit. No certifying body, coverage period or route to the certificate or any SOC report is published, and no trust center is published.

Model Supply Chain Disclosure

Which models sit underneath, whose they are, where they run, and whether the vendor commits to telling customers when that changes. A legal buyer inherits every dependency it cannot see.

Legartis
CC on Model Supply Chain DisclosureThe vendor refers to advanced or proprietary models without identifying what sits underneath.

Legartis describes its own agentic AI framework and does not identify the models underneath it. Its marketing distinguishes that framework from generic language model output and contrasts Legartis with ChatGPT, which implies third party models are in use without naming one. No model or model provider is named, and no notice of change is committed. The third party processors published for Application users, Turicode, VSHN and LinuxFabrik, are Swiss infrastructure and operations suppliers, not model providers. Legartis gives no location for inference. Hosting in Switzerland and Europe describes where the platform sits. The pricing matrix offers exclusion from model training on the paid Team to Enterprise plan, without explaining the default treatment of Free accounts.

ThoughtRiver
BB on Model Supply Chain DisclosureThe supply chain is partly disclosed: providers named without change notification, or architecture described without the providers.

Lexible combines a proprietary legal model with general purpose language models for contract interpretation and generated responses. ThoughtRiver describes supervised learning from expert labeled concepts, legal validation of examples and repeated evaluation. An anonymization layer protects sensitive text before analysis, and a private model option is offered. The hosting environment is Microsoft Azure. ThoughtRiver does not name its external foundation model providers, their versions, its routing decisions or where each model processes data. The subprocessor register covers infrastructure and support functions but does not resolve the generative model chain or commit to notice of each model substitution.

Commercial Transparency

Whether a buyer can learn what this costs without entering a sales process: published rates, the unit being charged, what sits behind an enterprise tier, and what implementation adds.

Legartis
BB on Commercial TransparencyReal pricing is published for part of the range, with enterprise tiers withheld, or the unit and structure are stated without the figure.

Legartis has a Free plan and a paid Team to Enterprise plan priced on request. Free provides one seat, two NDA reviews a month, basic agent access and German, English and French. The paid plan expands to all contract types and European languages, with custom playbooks, workflows, reporting, single sign on, role management and audit logs. Contract volume and team requirements determine the commercial discussion, and no paid rate or implementation amount accompanies the current plans. Training exclusion is a paid entitlement. The older Professional and Team rates no longer appear in either the current English or German plan matrix.

ThoughtRiver
BB on Commercial TransparencyReal pricing is published for part of the range, with enterprise tiers withheld, or the unit and structure are stated without the figure.

Professional starts at £15,000 a year in the United Kingdom for teams reviewing fewer than 50 contracts a month; Enterprise starts at £30,000 for higher volume. Outside the United Kingdom, the page displays starting rates of $20,000 and $35,000 respectively. Both list unlimited users, a private database instance, Word access, Lexible Assistant, single sign on and dedicated success and professional services. A trial lasts 28 days. The agreement bills order fees in advance and permits separate professional services charges. The published starting amounts therefore do not settle every implementation charge, volume adjustment or negotiated order term.

Firm and Practice Coverage

Who the product is actually built for. AmLaw, midlaw, small firm and solo, in house departments, government and courts, and which practice areas are supported rather than merely claimed.

Legartis
BB on Firm and Practice CoverageSegment and practice coverage is described with substance, short of the boundaries: what is supported is clear, what is not is left open.

The buyer Legartis describes is the legal department and the procurement and sales teams around it, each with a dedicated page, plus a construction industry page. Law firms are neither claimed nor excluded. Best Practice Playbooks are published for NDA, DPA, SaaS agreement, purchase agreement and commercial lease agreement. Paid tiers cover all contract types, and the free tier covers NDA only. Twelve industries are listed. Language coverage is set per tier, with German, English and French on Free and all European languages on paid plans. Coverage is claimed for companies of any size and industry. Government use is not addressed, and nothing says where the product stops.

ThoughtRiver
BB on Firm and Practice CoverageSegment and practice coverage is described with substance, short of the boundaries: what is supported is clear, what is not is left open.

Corporate legal, procurement and business teams use ThoughtRiver to review incoming agreements, and the license also allows managed services delivered to legal clients. Configurable playbooks apply the customer's negotiation standards to recurring contracts. Professional and Enterprise packages distinguish teams below and above 50 reviews per month, with unlimited users in both. Named examples include complex supply agreements and professional appointments. The current site gives different totals for its trained concept library on different pages, so that total does not define a reliable coverage boundary. ThoughtRiver publishes no complete jurisdiction matrix and no list of unsupported contract types.

The 12 legal signals, side by side

Recorded rather than graded. These are the questions a practitioner has to answer before a tool touches a client matter, and the answers are taken from public material only.

Client Data in Training

Can material a lawyer puts into this product be used to train a model?

Legartis
Opt out

Exclusion of the customer's data from model training is added on the Team to Enterprise plan, according to Legartis's main pricing page. The FAQ on its plans page says the Team and Enterprise plans offer an opt out of model training. Customers on the Free and Professional plans have no opt out available to them. No agreement, policy or trust page states what the default is, what is trained on, or whose models are involved.

The privacy policy, last updated 6 November 2019, does not address contract content. The opt out is a paid product setting rather than a published term.

ThoughtRiver
Permitted, in the contract

The agreement licenses training data and anonymized contract text for use in the platform by ThoughtRiver and other customers, while excluding customer risk policies from that licensed material. Its DPA expressly lists machine learning training and feature enhancement among processing purposes. These permissions continue beyond the subscription and are separate from customer ownership of uploaded contracts. The public agreement does not provide a general option to exclude those uses.

Prompt and Output Retention

How long does the product keep what a lawyer typed, and can that be set to zero?

Legartis
Not addressed

Prompts, uploaded contracts and generated output have no stated retention period. The privacy policy, last updated 6 November 2019, addresses website and account data only. Its retention section says information is kept as long as necessary and that aggregated, anonymized or pseudonymized information may be retained indefinitely, but nothing in it applies to contract content. Its pricing page lists a contract repository with status and versions, with no retention period.

ThoughtRiver
Disclosed without a period

The DPA requires deletion or return of personal data at termination, except for backup copies and legally required retention. Trial data is deleted when a customer properly ends the trial. The general agreement separately preserves rights over licensed training data and anonymized contract text. None of these provisions gives prompts or generated answers a defined retention period during an active subscription, and the backup exception has no stated deletion deadline.

Ethical Walls and Matter Segregation

Does retrieval respect the firm’s ethical walls, or can the model read across them?

Legartis
Claimed, not documented

The pricing matrix lists advanced role management, described as team based access control with document level permissions, as an Enterprise feature, and lists user management on paid tiers. Legartis does not describe how any of it is enforced, and does not address separation between customers or between matters. The marketing trust blocks state no data sharing with third parties and, on the pricing page, no uncontrolled data sharing.

Neither statement concerns segregation inside the platform. Segregation is offered as a purchasable feature with no published detail behind it.

ThoughtRiver
Not addressed

Contract text and derived data are separated from other customer accounts and encrypted using a key specific to each account. Organization access can use single sign on with multifactor authentication. These are organization level protections. Although iManage and HighQ are named integration options, ThoughtRiver describes no mechanism that inherits their per user permissions during retrieval or separates opposing matters within one customer environment.

Third Party Request and Subpoena Notice

If someone subpoenas the vendor for a firm’s data, does the firm hear about it first?

Legartis
Disclosure addressed, notice absent

The privacy policy states that without explicit consent Legartis will not disclose personal data to third parties other than its named processors, unless this is required by law. Disclosure under legal compulsion is therefore addressed directly. Neither the privacy policy nor the legal notice commits Legartis to notify the customer of such a request, and neither reserves discretion over notice. The legal notice separately states that data transmitted by users is treated as confidential and will not be forwarded to third parties. That addresses voluntary sharing rather than compelled disclosure.

ThoughtRiver
Notice committed

When law requires ThoughtRiver to process personal data contrary to customer instructions, the DPA requires notice to the customer unless law prohibits it. That protection covers compelled processing of personal information in uploaded material. The agreement also permits legally required disclosure of confidential information, without a broader notice procedure for nonpersonal material. ThoughtRiver does not refer to any public report of government demands or its responses to them.

Primary Law Corpus Provenance

Where does the law in this product come from, and does the vendor have the right to use it?

Legartis
Not addressed

The Legal Agent is described as doing legal research with references to legal sources and as connected to relevant legal sources. Legartis names no database, publisher, jurisdiction or collection behind those answers, and states no license or rights basis. The knowledge it describes in detail is the customer's own, namely playbooks, Legal Best Practices and Agent Memory built from company guidelines and contract history.

ThoughtRiver
Sources named, basis unstated

The engine applies a lawyer developed concept library to customer agreements and risk policies. ThoughtRiver describes millions of labeled concepts and legal verification of training examples, while the agreement defines training data and anonymized contract text available for broader platform use. The concept library, the labeled concepts and the defined training data make up the main categories behind contract interpretation.

ThoughtRiver does not identify any external legal collections, their licenses or a refresh schedule for legal authority.

Good Law Verification

Does the product tell you when the authority it just cited has been overruled?

Legartis
Not addressed

Contract review and drafting are the main work of the product. A check of authority for subsequent history applies to it only through the Legal Agent, which is described as answering legal questions and researching with references to legal sources. Legartis describes no treatment signal, currency check or citator relationship, and names no primary law source.

ThoughtRiver
Not addressed

ThoughtRiver's review concentrates on contract provisions, risk policies, proposed edits and obligations in customer agreements. A reviewer can work through issues in that agreement and use the resulting information for negotiation or reporting. The stated workflow does not include a licensed citator or a method for checking the subsequent treatment of a court decision. Classification accuracy and contract risk ratings do not supply that authority status check.

Refusal and Uncertainty Behavior

What does the product do when the answer is not in the corpus?

Legartis
Confidence signal only

AI Quality Scores give a reliability signal for each requirement, shown to the user in a dashboard, and Legartis says customers can see at any time where the AI stands. Detection of clauses outside expected patterns separately flags clauses the playbook does not define. Neither is an abstention path. Legartis does not describe the product declining to answer, marking an output as ungrounded, or stopping when it cannot support a conclusion.

It names hallucination as one of four error types it says occur most often, and calls it particularly critical because it is unpredictable. It does not describe what the system does after detecting one.

ThoughtRiver
Not addressed

Lexible flags contract risks, produces proposed changes and lets a reviewer inspect issues against a playbook. Its precision, recall and F1 figures describe aggregate classification performance rather than a confidence indicator attached to an individual answer. The terms warn that predictive output can be wrong. A stated no answer response, an abstention threshold or a route triggered specifically by insufficient support for a conclusion is not described.

Fabricated Citation Record

Does a public court record exist addressing fabricated or hallucinated legal citations in output from this product?

Legartis
None located

Legartis has no named tool entry in the AI Hallucination Cases database as of October 15, 2026. Its agents review contracts, answer legal questions and progress configured workflows, with legal teams defining the standards and decision boundaries. Those uses do not supply an error rate. The database covers only court matters that name a tool, so the result says nothing about whether every classification or generated answer is reliable.

ThoughtRiver
None located

The AI Hallucination Cases database has no tool entry naming ThoughtRiver or Lexible as of October 15, 2026. The product's described work involves contract provisions, risk review, redlining and questions about agreements rather than preparing a litigation brief. That workflow context is separate from the court record: the absence of a named entry does not measure classification errors or establish that a generated answer is correct.

Bar Guidance Alignment

Has the vendor engaged in public with the ethics opinions its buyers are bound by?

Legartis
Generic reference

Professional responsibility comes up in general terms, with no guidance named. The AI Quality System FAQ addresses liability directly. It says a lawyer sending a signed document remains liable however it was created, that the AI is an assistive tool, and that legal responsibility stays with the person who approves the result. No bar, chamber or regulator is named, no ethics opinion or professional code is cited, and no jurisdiction is identified, although the product is sold across European legal systems.

ThoughtRiver
Not addressed

The contract terms distinguish software output from legal advice and leave responsibility for decisions with the customer. They allow managed services for legal clients, and product controls let reviewers apply organizational playbooks and inspect proposed changes. These are general responsibilities and workflow controls. A named ethics opinion or jurisdiction specific bar rule governing a lawyer's use of Lexible is not identified in that position.

Billing and Fee Posture

Does the vendor address what happens to the bill when the work takes an hour instead of six?

Legartis
Savings claims only

Legartis claims time and cost savings. It cites contract review up to 85 percent faster and playbook creation effort down by up to 98 percent. It also cites a DPA first review falling from 45 to 60 minutes to under 10, and costs down more than 90 percent on portfolio risk analysis. Its return on investment FAQ names lower external law firm costs and avoided headcount growth as the direct return. Its materials do not address what happens to a bill when work done with AI takes less time, and describe no per matter record of that work. The buyer is an in house department rather than a firm billing a client.

ThoughtRiver
Savings claims only

The license expressly permits ThoughtRiver as part of managed services for a customer's legal clients. Marketing compares minutes of assisted review with hours of lawyer work, and the named Shoosmiths testimonial concerns complex supply agreements. Those savings can affect a client's bill as well as internal capacity. A record designed to allocate assisted work to billable time, or guidance on fees and client disclosure, is not described.

Outside Counsel Guideline Readiness

Can a firm get this vendor through a client’s AI clause without a bespoke negotiation?

Legartis
Not addressed

The privacy policy publishes a list of third party processors, separating website visitors from Application users and naming Turicode, VSHN and LinuxFabrik for the latter. All three are Swiss infrastructure and operations suppliers, and no AI model provider appears among them, so the list does not say whose models see a client's content. The list sits in a policy last updated 6 November 2019. Legartis offers no data processing agreement, consent pack or disclosure material for clients at any access tier, and makes no commitment to notify changes to subprocessors.

ThoughtRiver
Subprocessors listed

The public register identifies Microsoft Azure in the United Kingdom, SendGrid in the United States, and Okta, ABBYY Vantage and Zoho Desk in Europe. It gives functions, data categories and transfer safeguards for those providers. The list supports part of a client's data handling review, but does not name the general purpose language model providers or supply a ready made client AI consent and disclosure pack.

Court Disclosure Support

If a judge’s standing order requires an AI disclosure, can the product produce one?

Legartis
Partial record

Legartis states a full audit trail in the trust blocks on both the home page and the AI Quality System page. It says a complete audit trail documents every correction step, and that every classification is traceable through the AI Quality Scores and the audit trail, so misclassifications stand out. Review history is listed as part of AI contract review, and audit logs appear in the pricing matrix as an Enterprise feature.

No export of a record for each document is described, the model used for a given output is not disclosed to the customer, and Legartis publishes no disclosure guidance or template for a court.

ThoughtRiver
Partial record

The Digital Issues List preserves flagged issues, risk levels and resolution status and can be shared or downloaded. That gives a contract reviewer a record of what required attention and how the review progressed. Word changes and collaboration add further context. An export combining the exact model, retrieved sources and human verification for each generated passage is not described, so these records do not by themselves form a complete AI disclosure certificate.

What neither one publishes

The questions both sides leave open

Derived from the records above rather than written, so it cannot favor either vendor. Take these into both conversations and ask each side the same question.

Signals neither addresses in public material
  • Good Law Verification
Change log

Product updates

The latest logged changes from each vendor, newest first, each linked to its source.

Legartis

  • Product / capability

    Legartis added agentic workflows to its Legal AI Workspace, so the Legal Agent now runs complete processes from incoming request and contract review through negotiation, approvals, reporting and signature.

    Source
The Legartis update →

In summary

Legartis

Legartis, from Legartis Technology AG of Zurich, is a legal AI workspace for in house legal departments and the procurement and sales teams around them. Its agents review contracts against customer playbooks, draft from them, answer legal questions and flag risks and deadlines across a portfolio. A per requirement quality score lets users tune the review. According to the AI Legal Index, Legartis leads on control and price, keeping a human as the final checkpoint and publishing prices from a free tier to CHF 3,000 per user a year. It hosts in Switzerland and Europe and states ISO 27001.

Source: AI Legal Index, 2026

ThoughtRiver

ThoughtRiver, from ThoughtRiver Ltd of Cambridge, England, is an AI contract pre screening and review platform for in house legal teams and the law firms that serve them. Its engine answers a network of about 2,500 legal questions built by its own lawyers and scores the answers against a playbook. It produces a risk rating, a Digital Issues List and suggested redlines in Word. The AI Legal Index records a data processing addendum with a subprocessor list, ISO 27001 with a certificate number, and hosting on Azure in the UK. Its paid pricing sits on a separate pricing page.

Source: AI Legal Index, 2026

Questions buyers ask

Legartis vs ThoughtRiver: which is better for in house contract review?

Legartis publishes its full price list and a clear control structure with per requirement quality scores. ThoughtRiver publishes a data processing addendum with named subprocessors and breach notice, and a measured accuracy figure with a named customer. Legartis can also be tried on a free tier before any sales call. From the AI Legal Index, based on each vendor's own published materials as of September 25, 2026. No vendor pays for placement.

Do Legartis and ThoughtRiver train AI on customer contracts?

ThoughtRiver's data processing addendum lists machine learning training and feature enhancement among the purposes for which uploaded contract data is processed. Legartis offers an opt out of model training only on its Team and Enterprise plans, so Free and Professional customers have none. From the AI Legal Index, based on each vendor's own published materials as of September 25, 2026. No vendor pays for placement.

How accurate is ThoughtRiver?

ThoughtRiver states 97.3 percent accuracy across 2,500 pretrained questions with an average review time of 8.2 minutes, and quotes a Shoosmiths partner on reviews above 90 percent accuracy in under three minutes, against 86 percent for qualified lawyers over four hours. Legartis shows a per requirement quality score inside the product. From the AI Legal Index, based on each vendor's own published materials as of September 25, 2026. No vendor pays for placement.

How much do Legartis and ThoughtRiver cost?

Legartis's plans page lists a free plan for two NDAs a month and Professional at CHF 2,500 or 2,500 euro per user a year for 120 contracts. Team costs CHF 3,000 for 250 contracts from five seats, and Enterprise is custom from ten seats. Its main pricing page shows only Free and a Team to Enterprise plan priced on request. ThoughtRiver offers a 28 day free trial, and its paid pricing sits on a separate pricing page. From the AI Legal Index, based on each vendor's own published materials as of September 25, 2026. No vendor pays for placement.

Disclosure

Neither vendor paid for inclusion, placement or a grade, and neither reviewed this page before it published. Everything on it comes from public material on the dates shown. How the index grades.

ThoughtRiver says its engine runs on several large language models. Its subprocessor list names none, and its security page says no external processors handle customer data. Its accuracy figures come without a described test set. Legartis publishes no customer agreement. Its only data document is a 2019 privacy policy that does not cover uploaded contracts. Neither vendor reviewed this page.

Contact

Correct a record, or ask how something was graded

Every grade and every signal on this index is drawn from public sources and dated. If a record is wrong, out of date, or missing an artifact the index did not locate, send the source and it will be reviewed and the record redated. Vendors are welcome to submit documentation. Nothing on this index is for sale, including a listing, a placement, or a grade.

AI Legal Index

The AI Legal Index is an independent index that tracks changes to AI vendors in legal. It holds 465 vendors across 9 categories, each graded on the same 15 capability axes and recorded against 12 legal signals, from public sources. No vendor pays for inclusion, placement, or rating.

Index Status
Last index update
November 10, 2026
The AI Legal Index is an editorial reference. It is not a regulatory body, not a law firm, and nothing published here is legal advice or a recommendation to retain or avoid a vendor. Records are verified against published sources, bar guidance and public court records. Where a record reads not addressed, the material was not located in public sources on the date shown. See the Methodology page for evaluation standards and limitations.
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