Jus IA
Jusbrasil's AI that answers like a lawyer — and shows the source so you can check it.
By Thiago Lourenço Martins
The AI that won't let you cite a case that doesn't exist
Jus IA is Jusbrasil's AI assistant, built on top of Brazil's largest legal database. Think of it as an intern who has already read practically all of the country's case law and never sleeps — except before handing you any citation of a law or ruling, it checks whether that citation actually exists in Jusbrasil's database and shows you the link. That's the difference from a generic chatbot: it doesn't hand you nice-sounding legal prose, it hands you a source you can verify.
The nightmare of citing case law that doesn't exist
Lawyers have already been reprimanded — and hit with disciplinary proceedings — for pasting into a filing a court decision that AI simply made up. It's the kind of mistake that doesn't forgive: it stains the whole document and the credibility of whoever signed it.
According to Jusbrasil's own study, Jus IA outperforms generic AI in 70% of cases evaluated on legal tasks — because it was trained only on Brazilian case law, legislation, and legal scholarship, not the entire internet.
Five times you'd open Jus IA in a normal work week
Describe the case as if explaining it to a colleague and ask for recent case law on the topic — get back summaries with a link to each source.
Ask Jus IA to turn the conversation into a draft complaint or defense, with the parties, facts, and legal grounds already organized.
Attach a contract or a case file as a PDF and ask where the risky clauses are, before a meeting with the client.
Paste the docket number and Jus IA imports the cover sheet, parties, and case history on its own, without any manual copying.
Ask for a draft email explaining the case status in plain language, no jargon, ready to send straight to a non-lawyer client.
From a free account to your first cited case law
- Go to ia.jusbrasil.com.br
Click "Cadastre-se" (Sign up) — or "Entrar" (Log in) if you already have a Jusbrasil account.
- Create the free account
This step doesn't ask for a credit card; it already unlocks experimental access to Jus IA.
- Describe your case
Write as if you were explaining it to a colleague: the facts, the central legal question, and, if relevant, the court.
the more context, the more precise the answer - Attach documents if needed
Drop the case's PDF or contract into the conversation to ask for analysis or a summary.
- Check the sources
Every citation of a law or ruling comes validated, with a link — click it before pasting anything into a filing.
- Ask for the filing
With the conversation built up, ask Jus IA to organize it all into a petition, a legal opinion, or a summary ready for your review.
A ready-made request to drop into the chat
I'm going to explain a case to you as if you were a fellow lawyer: [describe the facts, the parties, and what has already happened in the case here]. Research recent case law from the higher courts on this topic, summarize the core holding of each ruling you cite, and at the end, list the 3 main legal risks on my side of this case.
You'll get case law with a link to each source, plus a list of risks that helps shape strategy before you write the actual filing.
What works and what trips people up in Jus IA
Do this
- Group conversations about the same client or case into a "Case" — it gains memory and deepens the context on its own for later questions.
- Paste the docket number straight into the chat — it imports the cover sheet, parties, and history without you typing anything.
- Always click the citation links before pasting them into a document — it takes seconds and avoids an embarrassing mistake.
Avoid
- Counting on the free plan for real work — it's only "experimental"; real research and real filings require a subscription.
- Forgetting that R$1.90 is only for the first month — from the second month on, the full price is charged automatically to your card.
- Treating the answer as final without reviewing it — Jusbrasil itself says Jus IA follows your reasoning, but doesn't replace the lawyer's decision.
A full test in Portuguese, straight from a user
* Independent suggestion, chosen for content quality. We have no relationship or sponsorship with the channel. Video is in Portuguese.
Bring a real (or fictional) case to the chat now
Grab a case you know well — yours or a client's. Open Jus IA, describe the facts as if explaining it to a colleague, and ask for recent case law on the topic, with a link to each source.
It worked if you get at least one ruling with a clickable link in under a minute — and if, when you click it, the link actually opens the original source.
My rating after asking for a real piece of research
rating 3.9 out of 5
I tested it with a common topic — constructive dismissal under Brazilian labor law — and the answer came back in seconds, with genuinely linked case summaries: I clicked three citations, and all three opened the original source on Jusbrasil. That already solves the biggest fear any lawyer has using AI today: citing a case that doesn't exist. The issue isn't the quality of the answer — it's the disguised entry price. The R$1.90 grabs your attention, but the real plan costs R$78.90 a month (R$58.90 on the annual plan), and the entry tier only unlocks 30 messages a month, which run out fast in a busy research week. For anyone researching almost daily, the Professional plan (R$108.90) is the one that pays off — except at that point the monthly cost matches a part-time junior associate.
Tested and checked against official sources on July 19, 2026.
What's in its favor
- Every citation of a law, ruling, or precedent comes validated with a direct link to the source on Jusbrasil — you can check it before pasting it into a filing, solving the real fear of citing a made-up case
- Built specifically for Brazilian law: it understands legal jargon and organizes the answer with a summary, grounds, and holding, without you having to rewrite the request from scratch
- Can draft the filing (petition, defense, appeal) already organizing the parties, facts, and legal grounds based on what was discussed in the conversation
- A database of more than 90 million rulings, plus access to more than 1,900 legal scholarship books on the Professional and Premium plans
Where it struggles
- The free plan only gives "experimental access" — to actually research and create a real filing, you need to subscribe starting at R$78.90/month (R$58.90 on the annual plan)
- The advertised R$1.90 is only for the first month; from the second month on, the full price is charged automatically to your card
- On the entry tier (Essencial), you only get 30 messages a month on Jus IA and 1 document per conversation — not much for anyone researching daily
- Only accepts credit cards as payment for individuals — no boleto or Pix on the individual plans
Who Jus IA is actually worth the invoice for
Worth it if you…
- Are a solo lawyer or at a small firm and were already considering subscribing to Jusbrasil for legal research — Jus IA comes bundled in at no extra cost
- Draft filings every week and currently lose time hunting for case law manually, tab after tab
- Are an intern or student at a legal clinic of a partner university — Jusbrasil has already announced partnerships with USP and UFBA
Think twice if you…
- Only need a legal answer once in a while — the monthly cost doesn't pay off for two or three questions a month
- Expect a free, unlimited legal AI — that doesn't exist, not in Jus IA and not in any serious competitor
- Already pay for ChatGPT or Claude for everything and only run into law occasionally — Jus IA's edge (validated Brazilian sources) may not justify a second subscription
What it actually costs to unlock Jus IA
Just a taste. Signing up on Jusbrasil doesn't ask for a card and unlocks experimental access to Jus IA — but it's limited. To research, draft filings, and attach case files for real, the subscription starts at R$78.90 a month.
R$0 — reading articles and legislation, the lawyer directory, limited access to case law, and experimental access to Jus IA. No card required.
R$78.90/mo (R$58.90/mo annual) — 30 messages/month on Jus IA, 10 uploads, 10 cases with memory, 3 scholarship lookups/month. Promo: R$1.90 for the 1st month only.
R$108.90/mo (R$78.90/mo annual) — 150 messages/month, 50 uploads, unlimited scholarship access, curated legal news. Jusbrasil's own recommended plan.
R$208.90/mo (R$138.90/mo annual) — unlimited messages and uploads, case insights and notifications, priority support.
Important detail: there's no standalone subscription just for Jus IA — it comes bundled into Jusbrasil's legal research plans. Official prices as of July 2026 (subject to change). All amounts are in Brazilian reais (R$), Jusbrasil's official currency.
Before you create an account
Is Jus IA free?
Not fully. Signing up on Jusbrasil is free and unlocks experimental access to Jus IA, but to actually use it — research case law, draft documents, attach case files — you need a paid plan starting at R$78.90/month (R$58.90/month on the annual plan).
Do I need a credit card?
Not to create the free account. To subscribe to a plan — even with the R$1.90 first-month promo — yes: individual payment is credit-card only, billed automatically every month.
Does it work in Portuguese?
Yes, it was built specifically for Brazilian law. The interface, answers, case law, and legislation it cites are all in Portuguese, based on Brazilian legislation and courts.
Does it work on mobile?
Yes. There's an official "Jus IA do Jusbrasil" app for Android and iPhone, which accepts voice questions with automatic transcription and receives files sent straight from WhatsApp inside a case.
Does Jus IA replace a lawyer?
No, and Jusbrasil itself is clear about that: it speeds up research and drafting, but the critical analysis, case strategy, and responsibility for the final document still belong to the professional.
Are the case law citations reliable?
According to Jusbrasil, yes: every citation of a law, court decision, or legal precedent is automatically validated against Jusbrasil's database before it appears in the answer, with a link so you can check the original source.
Other AIs, for when the task isn't legal
If the problem isn't a legal one, Jus IA isn't the right tool — it was trained for Brazilian law and nothing else. For writing an email, putting together a presentation, or chatting about anything day to day, ChatGPT is still more versatile. If you need to read and discuss a specific PDF — a contract, a bidding document — without relying on Jusbrasil's legal database, NotebookLM answers only from what you upload, for free. For general research on the open web (news, price comparisons, anything outside Jusbrasil's radar), Perplexity pulls that up instantly. And if what you want is more elaborate legal writing, with more nuanced argumentation, Claude writes better prose — just without the automatic source validation Jus IA has.
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