CoCounsel, the legal AI platform from Thomson Reuters, became one of the most prominent names in legal AI following an acquisition worth approximately $650 million USD. For lawyers working in Switzerland - in private practice or as in-house counsel - the name recognition does not resolve the practical questions: Where does the data go? Does it leave Switzerland? And does the tool cover Swiss case law at all? This article compares CoCounsel and CASUS, a Swiss legal AI platform, head-to-head - on features, data residency, and suitability for the Swiss legal market.
What is CoCounsel?
CoCounsel is an AI-powered legal research and document analysis tool from Thomson Reuters. It is deeply integrated into the Westlaw ecosystem and targets primarily the US and UK markets. The system answers legal questions using the Westlaw database, analyzes documents, and generates summaries.
CoCounsel's strength lies in the depth of its US legal content. Teams working with American case law get access to one of the most extensive legal databases in the world. For firms with a transatlantic or US-focused practice, that can be a real advantage.
Why Swiss law firms look for an alternative
Several structural factors make CoCounsel a poor fit for Swiss users.
US hosting and data transfer. CoCounsel runs on US infrastructure. For Swiss law firms and in-house legal teams subject to professional secrecy obligations and Swiss data protection law, this is a problem. In many situations, client data simply cannot leave Switzerland.
Westlaw dependency. CoCounsel works fully only with a Westlaw subscription. Teams without one pay for a tool that is significantly limited without its underlying database.
No Swiss case law. Cantonal and federal court decisions - the core material for day-to-day legal work in Switzerland - are not covered by CoCounsel. Anyone researching Swiss Code of Obligations, Civil Code, or cantonal law finds no usable foundation there.
Pricing and entry barrier. CoCounsel is positioned as an enterprise product with a correspondingly high price point, typically tied to annual contracts. For small and mid-sized firms, that is a real barrier.
What to look for in an alternative
Anyone using CoCounsel as a starting point and looking for an alternative for the Swiss market should evaluate:
Data residency: Is data hosted in Switzerland or the EU? Is there any US data transfer?
Swiss legal database: Does it cover Swiss case law - both cantonal and federal?
Document workflow: Can the tool work directly in Microsoft Word, where most contracts are drafted?
Workflow breadth: Legal research alone is not enough. Contract review, benchmarking against playbooks, due diligence extraction - these are daily tasks.
Zero Data Retention: Is data stored after processing or not?
CASUS as a Swiss alternative
CASUS, a Swiss legal AI platform, is built for exactly this context. Hosting is exclusively in Switzerland and the EU - no data transfer to the US. CASUS also offers Zero Data Retention and No Human Review (abuse monitoring opt-out): client data is not stored after processing and is not accessed by any human reviewer.
Swiss case law: 660,000+ decisions
CASUS's Legal Research mode searches a database of over 660,000 cantonal and federal court decisions - all cantons covered, supplemented by statutory law. Relevant legal reasoning sections are highlighted directly in the results; content previews appear inline within AI answers, with no need to click through to external sources. The output is a structured, source-based first assessment - not a generic internet answer.
Contract work directly in Word
CASUS works as a Microsoft Word add-in and as a web app. The AI contract review workflow identifies risks and red flags from the perspective of each contracting party, prioritizes findings by severity (low / medium / high), and delivers actionable drafting options - applied directly to the document without copy-pasting.
The Benchmark workflow checks contracts against internal playbooks or established standards (SPA, NDA, DPA) and surfaces missing clauses, gaps, and deviations as structured findings - including a percentage match score.
Agent Mode: execute changes directly
CASUS's AI Chat answers questions about the document and links answers to the relevant source passage. In Agent Mode, changes are executed directly in the document - insert clauses, rewrite text, adjust content - while respecting structure, numbering, and formatting.
AI Data Room for due diligence
The AI Data Room enables parallel analysis of dozens or hundreds of documents. Extraction fields are defined by prompt; output is tabular, ideal for Excel, due diligence, or compliance reviews. Anomalies - such as liability clauses without a cap or notice periods exceeding 12 months - are flagged and prioritized by risk.
Proofread: formal consistency before sending
The Proofread module checks spelling, grammar, Swiss spelling conventions (ss instead of ss), cross-references, definitions, annexes, and placeholders. It does not alter legal meaning - it is a quality and consistency check of the document.
Direct comparison: CoCounsel vs. CASUS
Criterion | CoCounsel | CASUS |
|---|---|---|
Hosting | USA | Switzerland / EU |
US data transfer | Yes | No |
Zero Data Retention | No | Yes |
No Human Review | Not confirmed | Yes |
Swiss case law | No | Yes (660,000+ decisions) |
Microsoft Word add-in | Limited | Yes (fully integrated) |
Contract review (Risk & Quality) | Yes | Yes |
Benchmark against playbook | Not documented | Yes |
AI Data Room | Yes (up to 10k documents) | Yes |
Proofread | No | Yes |
Ecosystem dependency | Westlaw subscription required | No external subscription needed |
Primary market | USA / UK | Switzerland / EU |
Who CASUS is best suited for
CASUS fits Swiss law firms and in-house legal teams that work with contracts daily and rely on Swiss legal sources. Teams with confidentiality obligations that rule out US data transfers need a tool with Swiss data residency - for CASUS, that is structural, not just a policy statement.
Firms with high volumes of due diligence work benefit from the AI Data Room. Teams that want to check contracts against their own playbooks use the Benchmark workflow. For daily research in Swiss decisions, the Legal Research mode replaces the laborious manual process.
CoCounsel remains the better choice for teams with a strong US law focus that already hold a Westlaw subscription and have no constraints around US hosting.
Try CASUS
CASUS offers a free entry point. Teams that want to see whether the platform fits their workflow can get started at app.getcasus.com/signup - no annual contract required, no Westlaw subscription as a prerequisite. Details on security architecture and data residency are on the security page.
FAQ
What is CoCounsel?
CoCounsel is a legal AI platform from Thomson Reuters, deeply integrated into the Westlaw ecosystem. It targets primarily the US and UK markets and offers AI-assisted legal research and document analysis.
What is the difference between CASUS and CoCounsel?
CASUS is hosted in Switzerland and the EU, transfers no data to the US, and covers Swiss case law with over 660,000 decisions. CoCounsel is built around US infrastructure and the Westlaw ecosystem and does not include a Swiss legal database.
Is CASUS compliant with Swiss data protection law?
CASUS hosts exclusively in Switzerland and the EU, does not transfer data to the US, and offers Zero Data Retention and No Human Review. For specific compliance questions, the security page provides further detail.
Can CASUS be used directly in Microsoft Word?
Yes. CASUS is available as a Microsoft Word add-in and allows contract review, benchmarking, proofreading, and AI Chat to be used directly in Word - without uploading documents to an external platform.
Does CASUS cover Swiss cantonal courts?
Yes. The Legal Research database covers over 660,000 decisions from all Swiss cantons and the Federal Supreme Court, supplemented by statutory law articles.
Does CASUS require a Westlaw subscription?
No. CASUS is independent of Westlaw or any other external database subscription. The legal data is integrated directly into the platform.
What document types does CASUS support?
CASUS supports contract review (e.g. SPA, NDA, DPA, service agreements), due diligence analysis across many documents, benchmarking against playbooks, legal proofreading, and legal research for Swiss law.
How does CoCounsel's pricing compare to CASUS?
CoCounsel is an enterprise product with a high entry price, typically structured as an annual contract tied to a Westlaw subscription. CASUS offers a free entry point at app.getcasus.com/signup; for current pricing details, direct contact with the CASUS team is recommended.
