Lexis+ AI Legal Research Platform & AI Assistant

General AI is AI that is not optimised for strict legal requirements. It can perform general-purpose tasks extremely well, such as drafting communications, structuring information, or analysing text. General AI is a useful tool for legal professionals, as it can help them supplement legal research, drafting, and analysis.​

Protégé now brings the power of General AI to the secure Lexis+ AI environment, so legal professionals can draft with greater control, explore broader topics, and tackle complex problems without leaving their trusted legal workflow.  Users can now choose from multiple configurations to suit to their needs.

Protégé now offers Legal AI, GPT-4o, OpenAI o3, GPT-5, and Claude Sonnet 4 configurations in Lexis+ AI. 

• Legal AI is optimised for legal accuracy and blends multiple LLMs from leading providers for the best legal use-case. The multi-model configuration grounds all responses in LexisNexis content and includes CaseBase's citations.​
• GPT-4o is an OpenAI general-purpose model, known for its speed, natural tone, and broad capabilities. In this configuration, users can access web search capabilities and CaseBase's citation checks.  Responses are not grounded in LexisNexis content.​
• OpenAI o3 is OpenAI’s well-rounded and powerful reasoning model. It excels in math, science, coding, visual reasoning, technical writing, and instruction-following. In this configuration, users can access web search capabilities, Deep Research capabilities, and CaseBase’s citation checks. Responses are not grounded in LexisNexis content.​
• GPT-5 is OpenAI’s flagship model, released in August 2025. In Protégé, the GPT-5 model is best for responses that require deep analytical thinking to support complex questions, strategic exploration, and refining arguments.  In this configuration, users can access web search capabilities, Deep Research capabilities, and CaseBase’s citation checks. Responses are not grounded in LexisNexis content. 
• Claude Sonnet 4 is Anthropic’s mid-tier Claude 4 model, optimised for speed, efficiency, long context reasoning, and precise instruction following. In Protégé, the Sonnet 4 configuration is best for producing thoughtful and well-structured responses to support everyday tasks, communication such as emails, business development, and brainstorming. In this configuration, users can access web search capabilities and CaseBase’s citation checks. Responses are not grounded in LexisNexis content.

We employ a “humans-in-the-loop” approach where SMEs, data scientists and engineers are evaluating prompt responses and making adjustments. This is in addition to the adjustments made based upon direct user feedback, highlighting a good or bad output within Lexis+ AI. We are using a team of specialty trained legal experts to test the model’s responses to likely use prompts using a test set of prompts. These experts are trained to evaluate language model output to ensure consistency and quality.

LexisNexis is considered a leader in data privacy best practices and has established data privacy principles, governance structures and control programs designed to ensure that data privacy requirements are met, personally identifiable information is protected, and individuals’ privacy concerns are addressed across all jurisdictions where we operate. Lexis+ AI uses private models, and no third party has access to it. User sessions are also secure, meaning that the input from one Lexis+ AI user doesn’t bleed into the output of another (to preserve client confidentiality). Our models are hosted in protected accounts in commercial-grade cloud infrastructure, so we can manage performance and security.

Lexis+ AI is being developed in a manner to ensure that the output always considers the most recent content available. The foundational LLM is not being updated on a continual basis using our new content, but the latest content is utilised through our RAG approach to ensure it is considered when developing the output.

Lexis+ AI includes the Protege Legal AI and Protege General AI features that users can toggle between. We regionalise hosting of our customers’ Legal AI documents, conversations and prompts to ensure that they are stored in Australia. General AI is currently not hosted in Australia as it draws upon a number of LLM’s that are not locally hosted. The same security and privacy guardrails are still maintained for General AI.

No personal data is being processed in our current offerings. We have a robust data protection process in place (and that’s been the case for a number of years) and we are working closely with our privacy and information security teams on an ongoing basis.

Lexis+ AI pricing varies based on factors such as the size of your organisation, specific capabilities required, and the scope of content access. LexisNexis offers customised pricing tailored to individual needs.​

For detailed pricing information, contact LexisNexis directly by submitting your information via form on this page or calling 0800-800-986. LexisNexis can provide a quote based on your specific requirements and offer guidance on the most suitable subscription plan for your practice.