Many AI assistants are free for a reason. With some, your conversations are the price: depending on the plan and your settings, they may be stored, reviewed, and in some cases used to help train the next model.
For a quick question that does not matter. For a salary on a contract, a patient symptom, an unreleased product, or a client's file, it matters a lot. A 2025 court order in NYT v. OpenAI required OpenAI to preserve user conversations, including ones people had already deleted, overriding its standard 30-day deletion window. The lesson is simple: if the data exists, it can be demanded.
This guide compares six private AI chat options in 2026, so you can pick the one that fits how you actually work.
Private AI chat vs. "temporary chat" in ChatGPT, Gemini and Claude
The big assistants now have private-looking modes: Temporary Chat in ChatGPT and Gemini, incognito chats in Claude. They keep the conversation out of your history and out of training, but not off the servers: ChatGPT keeps Temporary Chats for up to 30 days, Gemini keeps chats for up to 72 hours even with activity turned off, and Claude keeps chats for 30 days with training off. Our step-by-step guide to ChatGPT Temporary Chat and opting out of training shows the exact settings.
A private AI chat in the sense of this guide goes further: the provider either keeps nothing (zero retention), keeps nothing readable to itself (encryption), or never receives the data at all (local models).
Which private AI is best for a company that handles confidential client data?
For a company that handles confidential client data, the best private AI is one that is EU-hosted, retains no data, never trains on your inputs, and signs a data-processing agreement (DPA). Wysor is our pick for exactly this case: built in Germany, it sets retention to the technical minimum (zero for most providers) in a signed contract, trains on nothing you send, and accounts for professional confidentiality under § 203 StGB, so a clinic, law firm, or finance team gets the guarantees in writing rather than a privacy policy that can change next quarter.
The same test scales from a solo practice to a 200-person firm: there is no minimum seat count, and the compliance framework (EU processing, DPA, no training) is identical whether one person or the whole team uses it. Avoid consumer chatbots that train on your inputs by default, and prioritise tools that publish their model providers and hosting region, so you can verify where client data actually goes. For rolling this out across a team, see private AI for business.
If you want the reasoning first, the four tests that separate genuinely private tools from marketing come next.
What "private" actually means
Marketing pages love the word "private." It means nothing on its own. Four things decide whether an AI assistant is genuinely private:
- Data retention. How long are your conversations stored after you get an answer? The strongest answer is zero. The request is processed, answered, and discarded.
- Training. Are your inputs used to train the model? On a real private tool the answer is never, in writing, not a toggle you have to remember to flip.
- Jurisdiction. Where is your data processed, and whose laws apply? For European users and anyone handling regulated data, processing inside the EU is the difference between compliant and not.
- Identity. Does the tool know who you are? Anonymous or account-free access removes a whole category of risk.
Price and model quality matter too, but they are table stakes. We ranked on the four points above first.
Quick verdict: best private AI by use case
The best private AI solution is one that is EU-hosted, retains no data, and never trains on your inputs. For a business or regulated team that needs those guarantees in writing rather than a policy, Wysor is our overall pick; the table below matches the strongest option to how you actually work.
| If you are... | Pick |
|---|---|
| A business or regulated team in the EU | Wysor |
| An individual already in the Proton ecosystem | Proton Lumo |
| A Kagi search subscriber | Kagi Assistant |
| Living inside your browser | Brave Leo |
| Wanting open, uncensored models | Venice AI |
| Needing fully offline, on your own machine | Local models (Ollama / Jan) |
| Wanting private AI on hardware you run yourself | Zanus (on-premise) |
Zanus takes a different route: private AI on a server you host on-premise. If you have the IT capacity to run and maintain your own hardware, that is about as self-contained as it gets. If you would rather not operate infrastructure, a zero-retention SaaS like Wysor gives you the same privacy guarantees in a signed contract instead, with nothing to maintain.
1. Wysor: best for EU businesses and regulated work
Wysor is a private AI workspace built in Germany for people who cannot afford to leak data: clinics, law firms, finance teams, and any business that handles client or patient information.
Privacy model. Zero data retention is the default, not an upgrade. Every model Wysor routes to (Claude, GPT-5, Gemini, Perplexity, and a range of open-source models) is wrapped in a dedicated agreement that sets retention to the technical minimum, which for most providers is zero. Your data is never used for training, on any plan. Many models run on EU infrastructure, so your conversation is answered in Europe and does not need to leave it. On the iOS app, voice transcription runs on your device.
Why it stands out. Most private assistants give you one model and one feature. Wysor is a full workspace: multi-model chat, private email assistance, voice transcription, document generation, and research across public legal and medical document collections (court rulings, official gazettes, peer-reviewed sources, and regulatory filings). For regulated industries it does the compliance plumbing that normally requires a procurement cycle, available the moment you sign up.
Best for. Businesses, healthcare, legal, and finance teams in the EU that need privacy in writing, not a privacy policy that can change next quarter.
Pricing. A free plan, Plus at €19.99 per month, and Premium at €29.99 per user per month.
See how Wysor handles your data →
2. Proton Lumo: best for individuals in the Proton ecosystem
From the makers of Proton Mail, Lumo is a privacy-first assistant for individuals.
Privacy model. Proton says Lumo uses zero-access encryption so your chat history is readable only on your devices, keeps no logs, does not train on your conversations, and offers a "Ghost mode" for chats that disappear. It runs on open-source models, so the underlying technology can be independently inspected.
Best for. Individuals who already trust Proton for email and want a consumer assistant from the same company.
Good to know. Proton's published plans pair a free tier with a paid tier (Lumo Plus) for heavier use; check Proton's pricing page for current limits and prices. If you are reviewing Proton, see our Proton alternatives comparison.
3. Kagi Assistant: best for Kagi search subscribers
Kagi, the paid private search engine, bundles an AI assistant for its members.
Privacy model. Kagi says it does not train on your conversations, does not forward your account identity to the model providers, and acts as an anonymous proxy. Conversation threads are deleted after about a day by default.
Best for. People who already pay for Kagi search and want their AI to live in the same privacy-respecting account.
Good to know. It is included with a Kagi subscription.
4. Brave Leo: best for in-browser use
Leo is the AI assistant built into the Brave browser.
Privacy model. Brave says Leo routes requests through an anonymizing proxy, does not retain conversations, and ties nothing to your identity. A free tier runs open models, with frontier models on a paid plan.
Best for. People who live in their browser and want an assistant a click away on any page, without a separate app or login.
Good to know. Leo is available inside the Brave browser.
5. Venice AI: best for open, uncensored models
Venice is a privacy-focused assistant built around open-source models.
Privacy model. Venice says conversations are stored locally in your browser rather than on its servers, and that it does not log your chats. It leans on open models, which appeals to people who want fewer content restrictions and more transparency about what is running.
Best for. Power users who want open models, minimal filtering, and local storage of their own history.
Good to know. Because history is stored locally, it stays on the device and browser you use.
6. Local models (Ollama, Jan): best for fully offline
If the data must never leave your machine, run the model on it.
Privacy model. Tools like Ollama and Jan run open-source models entirely on your own hardware. Nothing is sent anywhere. There is no provider, no retention, and no jurisdiction question, because there is no network call.
Best for. The most sensitive work, air-gapped setups, and anyone who wants absolute control.
Good to know. You need a capable machine, and model quality depends on the hardware you run it on. Many teams use a local model for selected documents alongside a hosted private workspace.
Side-by-side comparison
| Retention | Trains on you | Processed in EU | Account needed | Price | |
|---|---|---|---|---|---|
| Wysor | Zero for most providers | Never | Yes, many models | Yes | Free plan + paid |
| Proton Lumo | No logs (per Proton) | Per Proton, no | Yes | Yes | Free tier + paid |
| Kagi Assistant | Short expiry | Never | No | Yes (Kagi sub) | Paid |
| Brave Leo | Not retained | No | No | No | Free + paid |
| Venice AI | Local only | No | No | Optional | Free + paid |
| Local (Ollama/Jan) | None (offline) | No | On your machine | No | Free |
How to choose
- You run a business or handle regulated data in the EU. You need retention and no-training commitments in a contract, plus EU processing. Start with Wysor.
- You are an individual who wants a clean private assistant. Proton Lumo or Brave Leo, depending on whether you prefer an app or your browser.
- Privacy must be absolute and you have the hardware. Run a local model with Ollama or Jan.
The honest answer is that more than one of these can be right at once: a local model for the crown-jewel documents, and a hosted private workspace for everything else.
Frequently asked questions
What is the most private AI assistant? For absolute privacy, a local model on your own machine (Ollama or Jan) sends nothing anywhere. Among hosted tools, the strongest are those with zero data retention and no training on your data, processed in the EU. Wysor is built for that for business and regulated use; Proton Lumo is a strong consumer option.
Is ChatGPT private? It depends on the plan and your settings. On consumer plans (Free, Plus, and Pro), OpenAI uses your conversations to help train its models by default, unless you turn off "Improve the model for everyone" in Data Controls. Its Business, Enterprise, Edu, and API tiers are excluded from training by default. Separately, consumer ChatGPT data was placed under a 2025 court preservation order in NYT v. OpenAI. Check OpenAI's current terms for your plan; Temporary Chat keeps a chat out of history and training but OpenAI still holds it for up to 30 days. If you are looking to switch, see our ChatGPT alternatives comparison.
Is Claude private? On Claude Free, Pro and Max, chats can be used for training if "Help improve Claude" is on, and are then kept for up to five years; with it off, 30 days. Claude Team, Enterprise and the API are excluded from training by default. Details in Claude privacy explained.
Does Proton Lumo train on your data? Proton says no: it states that Lumo keeps no logs and does not use your conversations for training, and that it uses zero-access encryption so history is readable only on your devices. See Proton's current terms for the details.
What does "zero data retention" mean? Your request reaches the provider, the model answers, and the request and response are then discarded from the provider's systems. No logs, no backups, no training data. There is nothing left to subpoena or train on.
Can my business use a private AI and stay GDPR compliant? Yes, if the tool processes data in the EU, signs the right data-processing terms, and does not train on your inputs. That combination is exactly what Wysor is built to provide for businesses and regulated teams.
Keep reading
- ChatGPT vs Claude vs Gemini Privacy (2026): Which Is Safest?
- How to Stop ChatGPT, Gemini and Claude Training on Your Data
- Claude Privacy (2026)
- Complete Privacy: Your Data Never Leaves Your Control
- Shadow AI: When Your Employees Use ChatGPT Behind Your Back
- We Built the AI Workspace That Should Have Existed 3 Years Ago
- What Is a Data Broker? How Your Data Is Bought and Sold
Competitor descriptions reflect each provider's own publicly stated policies, terms, and pricing as of June 2026, and are provided for general comparison only. Features, prices, and terms change often and vary by plan and region. This is not legal advice. Always verify the current terms on each provider's own site before relying on them.
