# Lumo AI by Proton — Private Assistant from Europe

> Privacy-focused AI assistant for productivity and information. (iPhone/iPad app by Proton AG.)

- Source: https://appshunter.io/ios/app/lumo-ai-by-proton/id6746714949 (this page in markdown: same URL + `.md`)
- Developer: [Proton AG](https://appshunter.io/developer/979659484)
- Category: Productivity
- Price: Free with in-app purchases
- Rating: 3.80/5 from 485 App Store ratings · 505 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.6 · 95 MB
- Languages: Russian, American English, Dutch, European Spanish, Italian, German (Germany), Polish, Brazilian Portuguese, Turkish, French (France) and 1 more
- Released: 2025-07-23
- Data updated: 2026-08-29
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/lumo-ai-by-proton/id6746714949/reviews.md

## What is Lumo AI by Proton?

Lumo is a zero-access encrypted AI assistant that keeps every conversation private. Your data is never logged, shared, or used to train models. Your chats are yours, and yours alone. 

Built by Proton, the privacy brand trusted by over 100 million people and the team behind Proton Mail, VPN, Drive, and Pass.

THOUGHTFUL HELP FOR ANY TASK
Lumo handles everything from quick questions to more complex work. Choose Fast for quick answers or Thinking for multi-step reasoning.

FAST, POWERFUL WEB SEARCH
Get precise, real-time answers in seconds. Lumo cites live sources so you can verify facts, dig deeper, and stay current on news, events, financial data, and more.

CREATE AND REFINE IMAGES AND FILES
Work with images and files just by telling Lumo what you need, from generating and editing images to analyzing documents. Connect your Proton Drive account for seamless access to stored files.

AI THAT EVOLVES OVER TIME
Lumo gets better every time you use it. Memory retains context and preferences across sessions, and you can set tones and styles to get the exact Lumo experience you want.

STAY PRODUCTIVE AND ORGANIZED
Projects give you dedicated encrypted spaces for tasks that span multiple chats, files, and instructions, while Custom Lumos let you create assistants tailored for specific tasks. Switch between light and dark modes for a more comfortable experience throughout the day.

GHOST MODE
For conversations where you want maximum privacy, choose Ghost Mode. Chats are instantly deleted once you close them for greater peace of mind.

PRIVACY YOU CAN VERIFY
Lumo is founded on zero-access encryption with no server-side chat logs, and never uses your data for profit or model training. Like all Proton products, Lumo is built and hosted in Europe and is fully open-source.

Lumo helps you stay productive, curious, and informed — without ever compromising your privacy. Start a confidential chat for free today.

For more information, visit our website: https://lumo.proton.me/about
Terms of service: https://lumo.proton.me/legal/terms
Terms of use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Our open-source code base: https://github.com/ProtonLumo/ios-lumo

## Key features

- Privacy-first AI assistant
- Boost productivity
- Satisfy curiosity
- Stay informed
- Secure data handling

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Lumo Plus (1 month) | $12.99 | per month |
| Lumo Plus (12 months) | $119.99 | per year |


## What do users think of Lumo AI by Proton?

Overall sentiment: negative

**Pros**

- 👍 Sophisticated knowledge base
- 🚀 Rapid evolution with quality
- 💡 Potential for vision-enabled model

**Cons**

- 🐛 Inability to answer basic questions
- 🔒 Privacy concerns with data processing
- 🐛 Inconsistent responses
- 🐛 Frequent sign-outs
- 🐛 Dark mode issues

**Commonly reported bugs**

- Slow sign-in page
- Lack of real-time data access

**Most requested features**

- Dynamic Type support for adjustable font size
- Secure access to Proton Drive files
- Ghost mode to ensure no chat history is saved
- Intuitive history clearing option
- App mode

## Recent user reviews (10 of 505)

All indexed reviews: https://appshunter.io/ios/app/lumo-ai-by-proton/id6746714949/reviews.md

### 5/5 — Melhorou muito

*2026-08-18*

Pra quem usa o Lumo desde o começo ele evoluiu muito e a premissa dele de ter mais privacidade e nao ter suas conversas usadas pra treinar modelos é bem interessante

### 4/5 — I miss lively Lumo.

*2026-08-17*

I wish I could keep Lumo out of the icon box in the loading screen, and make Lumo bigger and animated like it was before. Also, I really miss animated ghost Lumo.

It’s purely aesthetic and has nothing to do with the functionality, but the liveliness of Lumo was a very important part of the app to me. It made the app feel much warmer and cosier than stark apps for bigger companies LLM.

**Developer response:** Hi! Thank you for sharing your feedback. We'll make sure to forward it to our team so that it can be taken into consideration for future improvements.

### 5/5 — Tolle KI-App – bei uns im Alltag angekommen.

*2026-08-17*

Ich hab Lumo 2.0 vor ein paar Wochen installiert und muss sagen, es hat sich schnell bei uns etabliert. Mit anderen KI-Chat-Apps hatte ich immer mein Problem beim Thema Datenschutz und den wöchentlichen Chat-Limits. 

Was für mich wichtig ist: Alles ist Ende-zu-Ende verschlüsselt. Bei uns kommen auch mal gesundheitliche Fragen rein oder Sachen zur Schule der Kinder – da will ich einfach nicht, dass irgendwer mitliest oder Daten weitergegeben werden.

Mit Lumo 2.0 Lite mach ich die schnellen Sachen, kurze Fragen, kurze Texte, sowas. Geht fix und reicht völlig. Wenn's mal komplizierter wird, schalt ich auf Lumo 2.0 Max – das ist langsamer, aber dafür gründlicher. Bei Matheaufgaben vom Gymnasium meines Älteren oder wenn ich Arbeitsblätter vom jüngeren hochlad und mir was erklären lassen will, nehm ich Max.

Der Speicher ist neu und extrem nützlich – Lumo weiß beim nächsten Chat noch, in welche Klasse die Kinder gehen und welche Schule. Ich muss das nicht jedesmal neu erzählen. Klingt klein, ist aber im Alltag echt praktisch. Spart auch Tokens weil der Kontext bekannt ist. Hört sich selbstverständlich an kann nicht jede Ki und explizit nicht so genau wie Lumo 2.0.

Beruflich nutze ich es für Zusammenfassungen und Textarbeit, auch hier je nach Anspruch mal Lite, mal Max. Lange Gespräche werden automatisch zusammengefasst, Kontext geht nicht flöten.

Nicht alles ist perfekt, manche Antworten könnten besser sein, insbesondere das Wetter und ab und an braucht Max einen Moment lang. Aber für mich ist es aktuell die beste KI-App, gerade weil ich das Gefühl hab, meine Daten sind safe und ich hab noch nie die Limits aufgebraucht.

### 5/5 — Privacy first that earns your trust

*2026-08-17*

If you value privacy and ethical tech, Lumo is a no-brainer. It may not be the most feature-packed or powerful LLM out there, and the UX has room to grow, but that's not the point. What sets Lumo apart is what's happening behind the scenes: your data isn't being mined, scraped, or used to train models. You're not the product.

As a Proton user, subscribing is a given, the Plus plan is genuinely reasonable, there's no cap, and it pays off. The key is to invest time upfront: set up your projects and structure your work. Do that, and Lumo's responses are excellent.

It's not trying to be everything to everyone, and that honesty is refreshing. If protecting your data matters to you (and it should), this is the best AI assistant available.

### 3/5 — Recurso de Voz necessário

*2026-08-15*

O app tá até legal mais ele tá precisando de recurso de voz urgente, as vezes ele manda um texto enorme, que acaba dificultando o que eu tenho de fazer porque eu tenho que ficar com um olho lendo e o outro fazendo o que tenho de fazer

**Developer response:** Thank you for your review. We've shared your request with the team for future consideration. You can follow our blog and our social media channels for any news and updates.

### 5/5 — Super

*2026-08-13*

Cette intelligence artificielle a fait du progrès mais l’époque où le chargement été un petit sablier était bien 👍 continuer comme ça

### 5/5 — Lumo Evolved!! ⚡️

*2026-08-11*

At first Lumo felt pretty basic and clunky, especially with the UI. But version 2.0 with projects and custom agents is a solid upgrade! I gotta say its internal training is also substantially better in a lot of areas you’d least expect it. You can have massive outputs without truncation or  having the model overly redirect and reframe the conversations for further engagement. 

That last part is a solid win if you want a forensic level thinking partner and not a chat bot. When you add this, the persistent memory, and the fact that it’s fully private—it’s a huge win!

### 4/5 — No copying and pasting photos and files

*2026-08-08, version 2.0.1*

I wish Lumo allowed pasting photos straight to the app like Venice and other AIs; it would make life easier; sometimes I just want to paste a photo or PDF.

### 3/5 — Privacy at the cost of project capability - Lumo Conversation Limits

*2026-08-06*

1. Unpredictable cessation Lumo stops responding when context memory reaches an unknown threshold, varying unpredictably between ~60% and ~80%. There is no warning indicator, making it impossible to anticipate when a conversation will fail.

2. No proactive handoff Users cannot ask Lumo to prepare a summary before it stops responding. By the time the limit is reached, the tool has already ceased functioning, leaving manual recovery as the only option.

3. Reactive recovery workflow When Lumo stops:

Copy the last 2–3 messages from the failed conversation
Paste them (as raw text, not a summary) into a new conversation in the same project
Raw messages consume more tokens than summaries, giving the new conversation less available headroom from the start.

4. Progressively shrinking capacity Each successive conversation supports fewer exchanges before hitting the limit, as pasted content plus accumulated file tokens consume growing portions of the context window. This forces increasingly frequent restarts.

5. User bears the burden Managing these constraints—monitoring for unresponsiveness, copying content, restarting conversations—is manual and distracting, pulling focus from the actual project work.

**Developer response:** We're sorry to hear that. Does this happen with the newest version of our Lumo service? Please contact us via the support form on our website with more details so we can investigate the issues further.

### 1/5 — Battery juice

*2026-08-05*

It is terrible because it drained the battery so hard, including when I was only reading the information! It is terrible, terrible and terrible!!!

**Developer response:** That doesn't sound right. Why do you believe this is caused by the service? Have you received any error messages? Feel free to contact us through the contact form on our website so we can further investigate and properly assist you.

## Frequently asked questions about Lumo AI by Proton

### What does Lumo AI do?

Lumo AI is a privacy-focused artificial intelligence assistant designed to help users stay productive, curious, and informed. It aims to provide assistance without compromising user privacy.

### What are the key features of Lumo AI?

Key features include its privacy-first approach, assistance with productivity tasks, satisfying user curiosity, and helping users stay informed. It is developed by the team behind other secure Proton services.

### Is Lumo AI free to use?

The application is free to download and use, with the possibility of in-app purchases for additional features or services. Specific details on pricing for in-app purchases are not provided in the description.

### What platforms is Lumo AI available on?

Based on the provided terms of use, the application is available on Apple's platform, indicated by the reference to 'apple.com/legal/internet-services/itunes/dev/stdeula/'. Compatibility with other operating systems is not specified.

### How does Lumo AI ensure user privacy?

Lumo AI is developed by Proton, a company known for its commitment to privacy and security in services like encrypted email and VPNs. The app is designed to protect user data and privacy throughout its operation.

## Version history (last 5 releases)

### 2.0.4 — 2026-08-21

Photo Paste Pounces In. Paste photos straight into your message on iPhone. Copy an image anywhere, then long-press the composer to open the native edit menu and drop it in.

No Cat Naps Mid-Answer. The screen stays awake while Lumo writes, so you can read along without tapping to keep it alive.

iPad Sidebar Clawed Back. In windowed mode on iPadOS 26, the system window controls no longer cover Lumo's sidebar button, so it's easy to reach again.

Security Fur-tified. Behind the scenes hardening to keep your data where it belongs. Nothing for you to do.

### 2.0.3 — 2026-08-12

iPad Attachment Menu Un-fur-led - Tapping the plus button in the composer on iPad now opens the attachment menu instead of nothing at all. Adding files from your iPad works again.

### 2.0.2 — 2026-08-10

Die Katze aus dem Sack. Wähle direkt im Eingabefeld ein individuelles Lumo mit eigener Persönlichkeit, und deine aktive Auswahl wird als Chip angezeigt, damit du immer weißt, mit wem du sprichst.

Pfoten-perfekte Proportionen. Wähle das Seitenverhältnis für die Bilder, die du generierst, von quadratisch über breit bis hoch.

### 2.0.1 — 2026-07-07

Picture Purr-fect - You can now download images straight from your chats. The app saves them natively, so grabbing a picture just works.

Link and Let Link - Tapping an external link now opens it correctly in your browser instead of getting stuck in the app.

Sheet Cat-astrophe Averted - The model selection panel no longer stretches to full screen when opened with the keyboard up. It now sizes neatly to its content every time.

### 2.0.0 — 2026-06-30

Picture Purr-fect - Describe what you want, and Lumo generates the image right in your chat.

Whisker-Sharp Memory - Lumo remembers your preferences and context across chats, so you don't repeat yourself. Everything stays encrypted, fully in your control, and never used inside projects.

A Fresh Coat of Fur - New composer, animated background, app icon. A full visual refresh.

A Clearer Cat-alog - Choosing between Lite and Max is simpler, with a cleaner layout and better-organized options. When Max is busy under high demand, it's clearly marked so you always know what's ready to use.

No more claws for Concern - Add a file Lumo can't read and you'll know immediately.

A Long Tail - Long chats tidy themselves up automatically, so you can keep the conversation going without losing the thread.

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All apps by Proton AG: https://appshunter.io/developer/979659484

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-29.*