Lexiel 98.0% on the bar access exam: our own measurement
We put Lexiel through Spain's official bar access exam of July 2026 (152 scorable questions, graded against the Ministry's answer key) and published the raw data. Why specialized legal RAG matters.
The Problem We Cannot Ignore: Legal Hallucinations
In 2023, a New York attorney filed a brief stuffed with ChatGPT-invented court decisions. The judge imposed a $5,000 fine and the case went viral. Spanish bar associations issued warnings. The question hung in the air: is it safe to use AI for real legal work?
The answer isn't simply yes or no. It depends entirely on which AI you use and how it's built.
The Test: the July 2026 Bar Access Exam
To answer that question objectively, we put Lexiel through Spain's official bar access exam (July 2026 session, 152 scorable multiple-choice questions). We chose this exam for three reasons:
- Maximum difficulty: It's the reference legal exam in Spain, covering all branches of the legal system.
- Verifiable answers: Every correct answer is published by the Ministry of Justice with a definitive answer key.
- No shortcut possible: Questions require genuine legal reasoning about current law, not fact memorization.
We evaluated Lexiel with its production legal retrieval. The raw file is published on the benchmark page. We have not measured Maite AI or any other legal product.
The Results
| Tool | Correct | Score |
|---|---|---|
| Lexiel | 149/152 | 98.0% |
Evaluation was conducted using automatic grading against the definitive answer keys published by the Ministry of Justice (July 2026 session).
Why Lexiel Beats General-Purpose Models
The difference isn't the underlying AI model : Lexiel uses state-of-the-art AI models. The difference is the verified legal corpus powering it via RAG (Retrieval-Augmented Generation):
- 69 BOE statutes: Civil Code, LEC, LECr, Criminal Code, LOPJ, Constitution, regional statutes and more
- 1,868 rulings (Supreme Court + Constitutional Court) indexed with semantic embeddings tuned to Spanish legal terminology
- 1,176 Constitutional Court rulings from 1980 through 2025
- ~95,000 semantic fragments available for real-time retrieval
When Lexiel answers about Article 609 of the Civil Code, it doesn't generate freely: it retrieves the exact fragments from the real statute and builds the answer on that verified foundation. If it can't verify something in the corpus, it says so explicitly.
What Lexiel offers
Beyond the legal chat, Lexiel offers:
- Verified corpus of 1,950 sources: 69 BOE statutes, 1,868 rulings (Supreme + Constitutional Court), CENDOJ case law, all indexed with semantic embeddings.
- Hybrid RAG: Vector + BM25 search with Reciprocal Rank Fusion (RRF), per-article deduplication, and verification against official sources.
- Complete law firm platform: Legal CRM, Verifactu invoicing, client portal, procedure engine for automated briefs, time tracking, and automatic deadline management.
What the Benchmark Does NOT Measure
Honesty matters. This test measures pure legal accuracy. It doesn't measure:
- Response speed (Lexiel uses real-time streaming)
- Integration with daily law firm workflows
- Usability and learning curve
- Productivity features beyond chat
Those are aspects every attorney should evaluate with their own 14-day free trial.
Conclusion
The benchmark measures answer accuracy, not citation accuracy. Lexiel cites, checks citations against the source and flags the ones it cannot verify. No AI system is error-free: always check citations.
If you use legal AI for research, brief drafting, or client consultations, it's worth demanding the same standard you'd demand from a colleague: cite the source, and make sure the source is real.
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