Lumo AI is the only mainstream AI assistant built so that even the company running it cannot read your chats. It comes from Proton, the Swiss maker of Proton Mail and Proton VPN, and it wraps every conversation in zero-access encryption with a strict no-logs policy. Nothing you type is stored in a readable form, shared, or used to train models. That single design choice is what separates it from ChatGPT, Gemini, and almost everything else.
Proton shipped Lumo 2.0 on June 30, 2026, rebuilding the assistant from the ground up with a thinking mode, image generation, long-term memory, and answers up to 76% faster. We tested what it can and cannot do, dug into which models actually power it, and checked whether the privacy promise holds up. This review covers the models, the Lumo 2.0 changes, pricing, how it compares to the big names, and what Apple users should know before switching.
The Key Takeaways
- Zero-access encryption plus a no-logs policy means Proton itself cannot read your Lumo conversations, even the saved ones.
- Lumo 2.0 (June 30, 2026) added a thinking mode, image generation, persistent memory, and responses up to 76% faster.
- It currently runs open-weight models Qwen 3.5 a GLM 5.2, routed on Proton-controlled servers, not on any third-party cloud.
- A free tier works with no account, and Lumo Plus is $12.99/month (about $9.99/month billed yearly), below ChatGPT Plus and Claude Pro at $20.
- An independent audit calls it the “least open” open AI, and there is no native Mac app yet, only web and iOS.
What Is Lumo AI?
Lumo is a privacy-first AI assistant from Proton, the Swiss company behind Proton Mail and Proton VPN. It runs open-source models on servers Proton controls, protected by zero-access encryption and a no-logs policy, so your conversations are never stored in readable form, shared, or used to train AI. Proton AG is majority owned by the non-profit Proton Foundation, which is part of why the company leans so hard on privacy as its product, not a feature.
You can start chatting as a guest with no sign-up at all. Create a free Proton account and you get encrypted chat history across devices, more daily messages, and image generation. Lumo handles the usual assistant work, writing, summarizing, brainstorming, research, and light coding, and the whole pitch is that you get that help without handing your data to an advertising company.
Lumo, GetLumo, and Luma AI Are Three Different Things
Search results mix up three unrelated products, so it is worth clearing this up before you download anything. Lumo by Proton is the privacy assistant covered here. GetLumo is a separate content-creation app for scripts and social posts. Luma AI is a video and 3D generation tool with no connection to Proton at all. If privacy is your goal, the one you want is published by Proton AG.
What Models Does Lumo Use?
Lumo does not run one model. According to Proton’s own documentation, the models it uses currently are Qwen 3.5 a GLM 5.2 for text, plus Image-Turbo a FireRed-Image-Edit-1.1 for pictures. These are open-weight models that Proton hosts and optimizes on its own infrastructure, then routes each request to whichever one is best suited to the task. Earlier Lumo builds relied on a different lineup, including Mistral and OLMo 2, which is why many older reviews name models that are no longer current.
The routing matters more than any single model name. A quick factual question, a long reasoning task, and an image edit can each land on a different model without you choosing anything. The trade-off is that Lumo’s frontier ceiling sits below GPT-5.6 or Claude Opus, since open-weight models trail the top closed labs by a margin. For everyday writing and research that gap is small, but for the hardest coding or reasoning it shows.
What’s New in Lumo 2.0
The Lumo 2.0 release on June 30, 2026 is the version worth judging, and it is a real step up rather than a point update. Proton says it re-engineered the assistant from the ground up, and CEO Andy Yen framed the new thinking mode as the headline capability. According to Proton’s Lumo 2.0 announcement covered by TechCrunch, the update responds to most queries up to 76% faster than the previous version.
The practical additions are the ones you will notice day to day. There is a thinking mode for harder problems, image recognition so you can upload a picture for analysis, and image generation from a prompt. Projects now include user-controlled persistent memory, so Lumo can recall your preferences across sessions instead of starting cold every time. Web search is stronger too, which closes one of the biggest gaps the earlier version had against ChatGPT and Gemini.
How Private Is Lumo, Really?
This is where Lumo earns its reputation. Every chat is protected by zero-access encryption, meaning your data is encrypted in a way that only you can access, and Proton keeps no logs of what you ask or what Lumo answers. Saved conversations are encrypted too, so even Proton staff cannot read them. The service runs under Swiss privacy law with full GDPR compliance, and the client code is open source. You can read Proton’s own breakdown in its Lumo security model documentation.
For anyone handling sensitive material, legal notes, health questions, unpublished work, this is a different bargain than the mainstream assistants offer. ChatGPT and Gemini both retain and, depending on your settings, train on conversations. Lumo removes that entire category of risk by design, which is the strongest reason to use it.
The “Least Open” Caveat You Should Know
Proton markets Lumo as open source, but that claim deserves a footnote. The European Open Source AI Index audited it and called it the “least open” open AI assistant in its database. Only the app code is public. The model weights, training data, system prompts, and the routing logic that decides which model answers you are all closed. That does not undermine the encryption, which is verifiable, but it does mean you are trusting Proton’s word on how the system behind the curtain works.
Lumo Pricing: Free, Plus, and Business
Lumo is cheaper than the mainstream assistants, and the free tier is usable rather than a demo. The catch is that free limits on messages, image generation, and premium model usage arrive quickly if you lean on it daily. Here is how the plans break down.
| Plan | Price | What you get |
|---|---|---|
| Free | $0, no account needed | Limited daily messages, image generations, and premium model use; 1 Project |
| Lumo Plus | $12.99/mo (~$9.99/mo yearly) | Unlimited chats, more image generation, full model access, unlimited Projects and memory |
| Lumo for Business | Team pricing, billed annually | Everything in Plus plus team management and admin controls |
At $12.99 a month, Lumo Plus undercuts both ChatGPT Plus and Claude Pro, which sit at $20. If you already pay for a Proton bundle, Lumo access can come folded into that, so check what you own before adding a standalone plan.
Lumo vs ChatGPT, Claude, and Fello
Lumo does not try to win on raw intelligence, it wins on trust. The table below sets it against the two mainstream leaders and against Fello, the multi-model Mac and iPhone app, so you can see where each one fits. If you want a deeper platform breakdown, our guide on how the big three compare on Mac goes further.
| Lumo Plus | ChatGPT Plus | Claude Pro | Fello | |
|---|---|---|---|---|
| Price | $12.99/mo | $20/mo | $20/mo | $9.99/mo |
| Privacy | Zero-access encryption, no logs | Retains chats | Retains chats | Your keys, per-model choice |
| Models | Open-weight, Proton-hosted | GPT-5.x family | Claude family | Multiple, pick per task |
| Image gen | Yes | Yes | Ne | Yes |
| Native Mac app | No (web + iOS) | Yes | Yes | Yes |
The honest read is that Lumo is the best choice when privacy is the priority and a good enough answer beats the smartest possible answer. When you need the strongest coding or reasoning, or a native desktop experience, the mainstream tools still lead. For a wider view of the field, see our roundup of the best ChatGPT alternatives for Mac.
Using Lumo on Mac and iPhone
This is the one area where Apple users hit friction. Lumo has a polished iOS app and a full web app, but there is no dedicated native Mac app yet. On a Mac you run it in the browser or install the web app as a standalone window, which works well but lacks the system-wide shortcuts and menu-bar access that native clients offer. On iPhone the experience is clean and the encrypted history syncs across your devices.
If a native, always-available assistant on your Mac matters to you, that gap is worth weighing. Many Apple users pair a privacy tool like Lumo with a multi-model app so they are not locked to one vendor. Our guide to the best AI apps for Mac covers the native options, and if you like the privacy angle you can also run other privacy-minded models on your Mac.
Is Lumo AI Any Good? Our Verdict
Lumo is very good at exactly what it sets out to do. For writing, summarizing, research, and everyday questions, the answers are solid, the interface is calm and fast since the 2.0 update, and the privacy guarantee is the real thing rather than marketing. If you have ever hesitated before pasting something sensitive into ChatGPT, that hesitation disappears here, and that alone makes it worth a place in your toolkit.
The limits are just as clear. The open-weight models mean it will not match the frontier tools on the hardest coding and reasoning, the missing native Mac app is a real gap for Apple users, and the “open source” label is thinner than it sounds. Our take is to use Lumo as your private default and keep a stronger model on hand for heavy lifting. A multi-model Mac app like Fello AI lets you do exactly that, switching between models per task from one native window for $9.99 a month, so you are never forced to trade privacy for capability. You can compare that approach against the field in our best AI models guide.
Závěr
Lumo is the clearest answer yet to a simple question, can you get a capable AI assistant without giving up your data. For most people the answer is now yes, and at $12.99 a month it costs less than the mainstream options. Start with the free tier to test the fit, upgrade to Plus if the limits pinch, and pair it with a native multi-model app if you want frontier power and Mac integration alongside the privacy.
FAQ
Is Lumo AI free?
Yes. Lumo has a free tier you can use without an account, with limited daily messages, image generations, and premium model usage. Lumo Plus costs $12.99 a month, or about $9.99 a month billed yearly, and adds unlimited chats and full model access.
What models does Lumo AI use?
Per Proton’s documentation, Lumo currently runs the open-weight models Qwen 3.5 and GLM 5.2 for text, plus Image-Turbo and FireRed-Image-Edit-1.1 for images. Proton hosts them on its own servers and routes each request to the best-suited model.
Is Lumo AI actually private?
Yes. Lumo uses zero-access encryption and a no-logs policy, so Proton cannot read your chats, including saved ones, and your data is never used to train models. It runs under Swiss law with GDPR compliance. The main caveat is that its model routing and weights are closed, so that part relies on Proton’s word.
Does Lumo have a Mac app?
Not a dedicated native one yet. Lumo offers a polished iOS app and a full web app, and on Mac you run it in the browser or install the web app as a standalone window. If you want native Mac integration, pairing Lumo with a multi-model desktop app is the common workaround.
Is Lumo better than ChatGPT?
It depends on what you value. Lumo wins decisively on privacy and costs less, at $12.99 versus $20 a month. ChatGPT still leads on raw model power, the hardest coding and reasoning, and native desktop apps. For sensitive work, Lumo is the better pick; for maximum capability, ChatGPT stays ahead.
