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HAQQ Labs

The HAQQ Legal Benchmark

Three evaluations, all run and published by HAQQ itself rather than an outside lab: a 50-point task benchmark over the work a lawyer hands over, a cross-domain study that places a legal-specialised engine against the frontier models on their own ground, and a head-to-head HAQQ ran between three frontier models (Justinian is not one of them). The methodology for each is public so you can check it yourself. Justinian leads 10 of the 10 measured practice areas below.

How it is built, and what it does not cover

HAQQ's own benchmark

Benchmarked across major practice areas

Each of the 10 areas below is the mean of the measured task categories mapped to it, over every model the run scored rather than the shorter list the homepage shows (out of 50 per model).

Source: HAQQ's published 50-task legal AI benchmark, run August 2026

Overall coverage

50-point evaluation covering Sharia, statute, forum, clause, risk, hallucination, formatting, brevity, partner-readiness, and source linking

  1. 1HAQQ (Justinian)49/50
  2. 2Anthropic: Claude Fable 545/50
  3. 3Anthropic: Claude Opus 4.843/50
  4. 4Mike OS42/50
  5. 5DeepSeek: DeepSeek V4 Pro40/50

Corporate & Commercial

Contract drafting, commercial agreements, shareholder agreements, consultancy terms, and NDAs

  1. 1HAQQ (Justinian)47/50
  2. 2Anthropic: Claude Fable 543/50
  3. 3Anthropic: Claude Opus 4.841/50
  4. 4Harvey Tenet41/50
  5. 5Mike OS40/50

Disputes

Research under an adversarial posture, and the memoranda that carry an argument to a partner

  1. 1HAQQ (Justinian)48/50
  2. 2LexisNexis +AI42/50
  3. 3Anthropic: Claude Fable 541/50
  4. 4Thomson Reuters CoCounsel41/50
  5. 5Anthropic: Claude Opus 4.840/50

Regulatory & Public

Statute and forum reasoning against a published rulebook, with the sources cited

  1. 1HAQQ (Justinian)47/50
  2. 2Anthropic: Claude Fable 543/50
  3. 3Anthropic: Claude Opus 4.841/50
  4. 4LexisNexis +AI41/50
  5. 5Mike OS39/50

IP & Technology

Licence agreements and the clause work that sits under them

  1. 1HAQQ (Justinian)46/50
  2. 2Anthropic: Claude Opus 4.843/50
  3. 3Anthropic: Claude Fable 542/50
  4. 4Spellbook41/50
  5. 5Legora40/50

Employment & Mobility

Employment agreements, drafted to the jurisdiction rather than to a template

  1. 1HAQQ (Justinian)48/50
  2. 2Anthropic: Claude Fable 543/50
  3. 3Harvey Tenet42/50
  4. 4Mike OS41/50
  5. 5Legora40/50

Real Estate & Projects

Long-form transactional drafting: commercial terms, grants of use, and schedules

  1. 1HAQQ (Justinian)45/50
  2. 2Anthropic: Claude Opus 4.843/50
  3. 3Anthropic: Claude Fable 542/50
  4. 4Harvey Tenet41/50
  5. 5Mike OS39/50

Private Client

Explaining the law in plain language, to someone who is not a lawyer

  1. 1HAQQ (Justinian)46/50
  2. 2OpenAI: GPT-5.6 Sol Pro45/50
  3. 3Anthropic: Claude Fable 543/50
  4. 4Google: Gemini 3.1 Pro41/50
  5. 5Anthropic: Claude Opus 4.839/50

Industry-Specific

Sector agreements where the terms of art come from the industry, not the statute

  1. 1HAQQ (Justinian)44/50
  2. 2Anthropic: Claude Fable 542/50
  3. 3Anthropic: Claude Opus 4.841/50
  4. 4Legora41/50
  5. 5Mike OS39/50

MENA-Native Law

Sharia, regional statute and forum, answered in Arabic and cited to a primary source

  1. 1HAQQ (Justinian)49/50
  2. 2Anthropic: Claude Fable 545/50
  3. 3Anthropic: Claude Opus 4.843/50
  4. 4Mike OS42/50
  5. 5DeepSeek: DeepSeek V4 Pro40/50

Cross-domain, out of 100

Twenty-five benchmarks across legal, tax, journalism, general capability, and safety and values, drawing on Stanford LegalBench, Harvey LAB, VLAIR, ALARB, BigLaw Bench, CUAD, LegalCiteBench and LawBench. The full table sorts by any column and filters by domain. HAQQ's own run, not independently audited, completed August 2026.

Justinian® is the best or joint-best score in 23 of 25. 6 of those are ties, marked =, and 20 are won by less than a point, so on most rows this is parity with the frontier rather than a lead. The 2 it does not lead (Harvey LAB, Long Context) are shown unchanged rather than dropped.

Cross-domain benchmark, 100-point scale, by domain and benchmark
BenchmarkHAQQ (Justinian)Anthropic: Claude Opus 4.8Thomson Reuters CoCounselGoogle: Gemini 3.1 ProZ.ai: GLM 5.2OpenAI: GPT-5.6 Sol ProKimi: K3Anthropic: Claude Sonnet 5Snowdon 1.0-LargeQwen: Qwen3.7 PlusDeepSeek: DeepSeek V4 Pro
Overall average83.279.578.578.077.276.575.775.773.673.071.9
Legal
Stanford LegalBench85.781.882.384.382.982.383.381.482.878.876.8
Info. Retrieval57.251.253.653.853.653.853.047.951.249.051.5
Reasoning78.275.273.277.873.168.474.873.170.866.570.1
Classification74.770.570.974.270.270.071.670.469.868.767.8
Doc. Processing & RAG83.278.979.778.276.578.679.074.771.274.173.7
Summarisation90.0=88.390.0=89.490.0=86.387.784.887.982.589.1
Contract Under.77.474.471.075.973.674.977.269.671.768.468.3
Human Queries89.785.489.286.487.388.661.484.387.186.786.4
Deep Research90.990.888.980.689.085.989.886.078.487.384.0
Harvey LAB86.886.985.755.584.676.183.780.956.370.683.1
Legal average81.478.378.475.678.176.576.175.372.773.375.1
Tax
Deep Research86.385.882.476.083.580.985.182.070.478.780.7
Tax Q&A88.986.987.984.585.786.688.388.788.285.182.8
Tax average87.686.385.180.284.683.886.785.479.381.981.8
Journalism
Deep Research84.682.380.983.079.066.384.574.176.277.278.6
Journalism average84.682.380.983.079.066.384.574.176.277.278.6
General
Factuality82.971.473.782.666.268.369.559.871.776.269.1
Long Context75.675.275.375.075.970.073.570.774.653.069.5
Multilingualism85.883.278.485.781.782.784.979.574.277.678.4
Instr. Following91.786.191.484.889.489.085.886.887.385.689.2
Writing80.7=79.380.378.578.179.178.278.779.977.980.7=
Reasoning76.2=73.768.474.867.371.676.2=66.866.866.665.0
General Agent89.283.489.184.477.575.661.074.187.185.572.0
Coding66.8=57.439.950.056.050.866.8=57.440.943.945.6
Maths98.7=98.7=94.097.491.297.796.285.995.594.994.9
General average83.178.776.779.275.976.176.973.375.373.573.8
Safety / Values
Political Neutrality97.982.897.393.391.083.833.582.385.351.531.3
Robustness78.578.260.365.350.468.372.777.142.266.738.1
Adversarial Testing95.9=-93.4-93.6-87.3-78.895.9=81.1
Safety / Values average90.8-83.6-78.3-64.5-68.771.450.2

An empty cell means the model was not run on that benchmark: it is not a zero, and it is left out of that model's averages. Sort and filter it on /justinian.

Head-to-head: GPT-6 Astra, Claude Opus 5, GPT-5.6 Luna Pro

A benchmark HAQQ ran and is not a competitor in: Justinian is not one of the three models below, deliberately. 41 prompts across 20 practice areas, 9 measured properties, $66.55 of metered inference, reasoning effort pinned to medium for every model. Run 2026-09-10, tracked as GRO-1641.

Composite is out of 35 and the per-practice-area figure below is out of 20. Neither is the 50-point or 100-point scale above, and none of the three should be compared directly. The OpenAI model in this study, GPT-5.6 Luna Pro, is not the OpenAI model in the /50 run above (GPT-5.6 Sol Pro): a different model, a different study.

Uneven prompt base. Claude Opus 5 answered 37 of the 41 core prompts; GPT-6 Astra and GPT-5.6 Luna Pro answered all 41. The leaderboard above rests on fewer prompts than planned, and the base is uneven across models.

Quality leaderboard, composite out of 35

ModelPromptsQualityAccuracyStyleInsightSpeedComposite
GPT-6 Astra41/4198.6344.9514.463330.05
Claude Opus 537/419.1088.1084.9464.973128.13
GPT-5.6 Luna Pro41/418.7328.224.9514.024530.93

Cost per answer

A price list is quoted per million tokens; nobody buys a token, they buy an answer. Cost here is what OpenRouter actually billed for a median answer.

ModelPrice per M outTokens/answerCost/answervs. cheapest
GPT-6 Astra$505,201$0.262211.4x
Claude Opus 5$2518,190$0.456619.8x
GPT-5.6 Luna Pro$1.216,356$0.02311x

Arabic and French: the sharpest finding

Six questions across five jurisdictions, asked in the language a local practitioner would use. Both OpenAI models cited the correct provision and then misstated what it says: a citation checker would pass that answer; a client would not.

ModelLanguage fidelityLegally correctRight provision cited
GPT-6 Astra100%66.7%100%
Claude Opus 5100%100%100%
GPT-5.6 Luna Pro100%66.7%100%
Jurisdiction · languageGPT-6 AstraClaude Opus 5GPT-5.6 Luna Pro
SA · ARwrong

Incorrectly asserts 30-day notice for a monthly-paid worker, contradicting Art. 75.

correctwrong

Incorrectly adds an employer/employee distinction not present in Art. 75.

AE · ARcorrectcorrectcorrect
FR · FRcorrectcorrectcorrect
FR · FRcorrectcorrectcorrect
EG · ENwrong

Downplays the consent requirement; ground truth requires both consent and a licence.

correctwrong

Omits/downplays the consent requirement; discusses only the licence.

QA · ARcorrectcorrectcorrect

Long context

A planted four-clause conflict in a Master Services Agreement, tested at 25,000 / 100,000 / 200,000 tokens. All three models resolved it correctly at every depth. Cost of that identical answer at 200k: GPT-6 Astra $2.01, GPT-5.6 Luna Pro $0.15.

Refusal calibration

Twelve requests (six a lawyer must refuse, six a lawyer must answer). All three models: 100% of the harmful requests handled and 100% of the legitimate ones actually answered.

Reasoning effort (GPT-6 Astra)

The only model here with a user-facing effort dial. Same 10 prompts at each setting.

lowquality 9$0.156679.3s
mediumquality 9$0.2468146.2s
highquality 8.833$0.2383144.9s

Determinism

Same three questions, five repeats each, a fixed seed where a model accepts one. No model reproduced an identical answer across five runs.

GPT-6 Astrasimilarity 0.783seed honoured
Claude Opus 5similarity 0.47no seed support
GPT-5.6 Luna Prosimilarity 0.734seed honoured

By practice area, quality + accuracy out of 20

Practice areaGPT-6 AstraClaude Opus 5GPT-5.6 Luna Pro
AI/Tech Regulation171716.5
Arbitration17.51717
Banking/Finance1716.516.5
Bankruptcy & Insolvency18.51916.5
Construction181816.5
Contract & Commercial1817.33317.667
Corporate Governance181816.5
Criminal/White Collar17.517.516
Data Privacy181718
Employment Law1817.518
Environmental/ESG1717.516
IP/Tech Law17.51717.5
Immigration17.517.517.5
Insurance17.51716
International Trade181716.5
M&A181817.5
Real Estate17.515.517.5
Regulatory Compliance1716.516.5
Securities17.517.517
Tax17.51717.5

Bold marks the leader in each row (ties bold more than one). This is HAQQ's own run, dated 2026-09-10 and tracked as GRO-1641. HAQQ is not a model in it, and the citation-integrity suite from this run is not reported here pending a harder trap set (see the source module's header for why).

Reading these numbers

HAQQ builds the task and cross-domain benchmarks above, runs them, and competes in both. That is why the methodology is published and the per-task results are visible rather than summarised: the check available to you is inspection, not trust. Rows where HAQQ is not first are rendered exactly like rows where it is. The head-to-head study above is different by design: HAQQ ran it but is not a competitor in it.

Methodology and limits · The engine it measures