Claude vs Lexiel : same model, very different results

Lexiel is built on Claude Opus. However, Lexiel's specialized legal RAG (BOE, CGPJ, 20 countries) pushes accuracy from 94% to 99.3% (144/145 questions) on the Bar Exam and achieves 98.4% on the Judiciary Exam (253/257). More than the model itself, what matters is the corpus and context engineering.

Try Lexiel free for 14 days 5 free questions, no sign-up

Official legal benchmark (Mar 2026)

Bar Exam: 99.3% (144/145). Judiciary CGPJ: 98.4% (253/257). Combined: 98.8% (402 questions). Model: Gemini 3.1 Pro with RAG. Modelos evaluados por Lexiel sin RAG jurídico (Mar 2026). Lexiel usa IA de última generación + RAG propio.

99.3%

Lexiel

With legal RAG

94%

Claude

Without legal RAG

Lexiel: +5.299999999999997% accuracy advantage

See full methodology and questions →

Lexiel vs Claude: key features

Evaluation based on publicly available information as of Q1 2026.

Feature

Lexiel

Claude

Real-time verified legal citations

Up-to-date BOE + CGPJ database

Specialized in Spanish & LatAm law

GDPR · EU-based servers

Hallucination prevention guarantee

Devil's advocate (counter-arguments)

Procedural deadline calculation

Integrated legal CRM

Invoicing with VAT/tax + VeriFactu

Client portal

Procedural workflow engine

Multi-jurisdiction (20 countries)

Included Partial / limited Not available

FAQ: Claude vs Lexiel

Is Claude reliable for Spanish law queries?

Claude is a general-purpose AI without a verified Spanish legal corpus. It cannot access BOE or CGPJ, may invent non-existent articles or rulings (hallucinations), and does not verify citations against official sources. Lexiel scores 99.3% on the Bar Exam (144/145) and 98.4% on the Judiciary Exam (253/257) through its specialised legal RAG.

Is Claude GDPR-compliant for law firms?

Claude processes data outside the EU by default. For a law firm, this raises risks under GDPR (Art. 28) and may compromise attorney-client privilege. Lexiel hosts all data on European servers (Madrid) and does not use user data to train models.

Can Claude draft court briefs with BOE citations?

Claude can generate legal-looking text but cannot verify that citations are real. The risk of presenting a non-existent ruling or article in court is significant. Lexiel generates briefs with citations verified against BOE and 1,868 CENDOJ rulings, with reference to the original source.

Convinced? Try Lexiel for free.

14 days free. Cancel anytime. Legal corpus from 20 countries. Support in Spanish.

Start · 14 days free 5 free questions, no sign-up