Lumo AI by Proton Reviews: Is It Legit?

Customer Experience

Positive experience45.9% of reviews
Neutral18.3% of reviews
Negative experience35.8% of reviews

~ Based on 575 written reviews from the US App Store.

What users say about Lumo AI by Proton

Is Lumo AI by Proton Safe?

Lumo AI by Proton appears mostly safe based on user ratings. AppsHunter Safety Score for Lumo AI by Proton is 77/100.

This assessment is based on 558 user ratings, with an App Store average of 3.8/5.

Safety Analysis

67.5% of ratings point to a safe experience
10.4% of ratings suggest some concerns
22.1% of ratings point to a risky experience

~ Based on 547 App Store ratings for Lumo AI by Proton.

Is Lumo AI by Proton Legit?

Lumo AI by Proton appears to be a legitimate app. AppsHunter Legitimacy Score for Lumo AI by Proton is 88/100.

Based on 88 of 100 points across 7 verification signals from App Store and developer data.

Top reviews

Major step forward

The first iteration was disappointing but this is now an entirely usable app. It’s not Claude Fable or Opus (Oct 2026), but it’s a fair balance between privacy and intelligence. And it wasn’t, it appears, trained on material that came from pirated material. We don’t need Lumo to be at the frontier: we just need it to be within viewing distance of it so that the trade off between privacy and “not falling behind” is viable. Good job.
Show more

Très efficace !

Excellente IA qui préserve la vie privé et donne des réponses très rapides et très pertinente 👌🏻

I tried

After a few chats, it told me that I had used up my quota of questions. I didn't create an account, so maybe that is a thing. But considering that it uses an old model of AI without an account, I don't see how it can compete with the DDG browser and its private AI chats. I haven't found any such limits there, and the model are new. What is the benefit of this app over that one? Can you please explain

--------
OLD REVIEW:

As long as you recognize that the information that Lumo gives is outdated, you'll be fine.

At least they dropped the "every word's a pun" garbage and chose to prioritize selling what they're selling instead of selling bad puns.

-------------------

I want to update but I couldn't understand what the dev was trying to say in the update description. Maybe next time I'll be able to take this app seriously. I have no idea if it is AI slop or if the app's a joke
Show more

W

Not bad I have used it for a few months only thing I would ask for a change is make it so it stops giving you a table ever time u send a message

No longer private

Tested Extremely rare, never mentioned anywhere else topics on lumo, minutes later the specific answers are given as you tube video suggestions.
This app is selling your data.
Not data profiling: i never mentioned the topic ever before on lumo.
Not cross sdk tracking: i don’t have any google or meta or other products. And i never mentioned the test subjects.
No one else on the network,
No smart devices on the network.
Lumpo is selling your data in real time
Show more

Response from developer

We do not keep logs of your activity in Lumo, and we don’t have access to your encrypted chat history, so we can never share it or leak it to third parties. Your conversations with Lumo are protected with zero-access encryption, meaning only you can access your data. Every conversation you save is encrypted in a way that can only be accessed by you, on your device. We don’t log or record your conversations. With respect to processing, the server-side model is running on machines operated by Proton. To learn more about the privacy of Lumo, navigate to https://proton.me/support/lumo-privacy. If you have any additional questions or concerns, feel free to reach out to us via the contact form on our website so we can further help.

So far so great!

I’ve loved my first few days with this app so far! Adorable cat and super helpful AI

Off to other platform as much to be desired

Updated Oct7 to add: I’ve exported everything to use another platform because lumo is subpar. Paying for the privilege of tools uncompetitive in the market was not on my bingo card for lumo or Proton as a business customer.
The worst part is I’m paying for Lumo to constantly fabricate throughout chats, sometimes so subtly you miss it and then get half way through before it’s clear.

Leaving much to be desired. Slow menu bar still requires waiting for 20+ seconds to appear.
Still unable to recognise proton files, requiring business users to download proton files natively to Microsoft or Google files and then paste into chat. No PNG or JPEGs are readable.
Lumo’s own project folder architecture is unable to read anything within a project so you are uploading file after file even if in the same project making it useless.

I’ve just exported everything to use another platform because it’s subpar. Paying for the privilege of tools not competitive in the market was not on my bingo card for lumo.

iOS App Opens to Blank Chat — Menu Unresponsive on Launch:

Sharing issue here because the app is not responsive, despite everything being up to date Aug26. Will update when it’s fixed.

Side note: the fact that you can’t upload proton documents into lumo is an absolute failure. Your own suite of programs don’t talk to each other - I have to export a Proton document to a Microsoft or Google document to upload into Lumo! I chose to migrate to Proton to divest away from these American products.

When I open the Lumo app on iPhone, it always opens to a blank chat screen. The menu showing my Projects and chat history does not appear automatically. I have to tap the screen repeatedly for approximately 20 seconds before the UI becomes responsive enough to access the menu.

**Steps to Reproduce:**
1. Close the Lumo app completely (swipe up from app switcher)
2. Tap the Lumo icon to relaunch
3. Observe blank chat screen with no visible menu
4. Attempt to tap screen/tap menu button — no response
5. Continue tapping/waiting ~20 seconds until UI finally loads

**Impact:**
This adds unnecessary friction every time I open the app. It feels like a bug rather than intended behaviour, especially for an app that should prioritise quick, seamless access.

**Expected Behaviour:**
- A menu button or sidebar icon should be visible immediately on launch
- Or, at minimum, the app should show the chat/menu list without requiring repeated taps and a 20-second wait

**Environment:**
- IPhone 13
- Lumo Plan: Business

**Request:**
1. Fix the unresponsive launch behaviour
2. Consider showing a cached/unencrypted menu structure on launch while encrypted content decrypts in the background
3. Confirm whether this is a known issue or a bug that needs investigation
Show more

Response from developer

Thank you for the detailed feedback. Regarding the slowness of the application, we're sorry to hear that this is happening on your side. We'll make sure to escalate this to our team. As for the rest of the feedback and the features mentioned, we'll add your vote so that our team is aware of the demand.

Censored

Works well, but it’s definitely censored. If you ask a politically incorrect question it’ll just refuse to answer.

Will Lie and bs

I asked for a part of a Bible verse and when it contradicted itself it , IT created a whole new verse! When confonted it replied with sorry i lied. Had more situations, it will decieve!

AI Assistant

Great that it thoroughly tells you how it is compiling its answers

Lumo: The Genius in my Pocket.

Whenever. Wherever. Whatever I need help with in a hectic day, Lumo is what I reach for in my pocket.
My trustworthy genius Lumo is always there.

Not fancy. Just genuinely Reliable, Respectful, Trustworthy. Answers when I ask. Remembers what we talked about. My stuff always stays private.

I've tried many — hands down, Lumo is the best out there — have earned my trust.
Honestly — Lumo is the only AI you ever need.
Thank You to the brilliant Proton engineering team for Lumo.
Show more

Crashes

Frequently crashes especially when I try and use the voice input.

Response from developer

That doesn't sound right. Could you share more details about the issue? Are you receiving any error messages? What are the exact steps you're taking that lead to the crash? Contact us via our support page with more details so we can help you troubleshoot.

Pretty good

Works as advertised. There's an odd problem with the app... changing(?) a few seconds after start up. The whole app redraws itself on the homepage and the menu button in the top left pops in and out of existence. But the chat works, Lumo is cute (I hope that's the kitty's name), and I trust Proton more than the American guys.
Show more

Doesn’t work as before iOS 27.0.

I upgraded my iphone to iOS 27.0 and the Lumo doesn’t work as before. It is not loading vidial cat and I can’t send my questions. I’m receiving response in red rectangular: “Something went wrong. Try again”. After reinstalling application or rebooting my iphone works fine for while, but it’s stops working soon.
Show more

Response from developer

That doesn't sound right. Please contact us via the contact form on our website so we can better help.

手堅い猫🐈‍⬛

一般向けプランの Proton Unlimitedに付属するLumo AI Plus、ビジネス向けプランの Proton Workspace Premiumに付属するLumo AI Proを使用しています。

フリープランだと、チャット履歴が1週間くらいで消え、Web検索はしないです。
他のAIツールはフリープランでチャット履歴が消されないし、Web検索してくれるので、課金させるためのビジネス戦略です。
チャット履歴が消えるのが困るので課金しましたが、プライバシーを売りにしている企業がこういうユーザーを釣るようなやり方をするべきでないと思います。
8月にSNSで話題になった価格変動調査をしたやり方も同様です。
Protonのプラン変更をしようとしたとき、画面を表示するたびに表示価格が変わる事象がありました。
Protonを信用して使っているので、こういうユーザーを騙したり引っ掛けたりするようなことはして欲しくないです。

概ね機能に満足しています。
猫みたい落ち着いた口調で淡々と会話します。
猫と会話をしている感じを楽しめます。
提案される内容が手堅い印象で、説明が丁寧です。
ただ、こだわりが強く、説明が長く感じるかもしれません。
Lumoのこだわりで、検証をさせられて時間が取られることが何回かありました。
使っていくうちに疲れてイライラするかもしれません。

この前、iPhone 17が発売されているのに知らなかったのでびっくりしました。
E2EEのAIツールは非E2EEのAIツールみたいにリアルタイムでモデル更新しないと思うし、開発リソースが大手より少ないと思うので仕方がないところがあるかもしれません。
どのタイミングでモデル更新されるのか知りたいです。
なので、情報の鮮度を求めるなら非E2EEのAIツールを使ったほうがいいかもしれません。

画像生成については、生成される画像が子供っぽいかもしれません。
キャラクターが身に付けている服やバッグのブランドロゴが、お店の看板など他のものに反映されやすいです。
プロンプトの書き方によるかもしれませんが、指示通り修正できない場合が多く感じます。
他のメジャーなAIツールもそうですが、だんだん検閲が厳しくなってきています。
精度や仕上がり、制限を考えると、画像生成はStable Diffusionなどの別のツール使用したほうが良いかもしれません。

ちなみに一般向けプランのProton UnlimitedにはLumo AI Plus、ビジネス向けのプランのProton Workspace PremiumにはLumo AI Proが付属し、機能が少し異なります。

★9/27追記★

最近はChatGPTを使っています。
比較するとChatGPTのほうがレスポンスが早くて優秀です。
Lumoは悪くはないてすが、こだわりが強く、真面目過ぎる、説明が冗長です。
画像生成もChatGPTのほうが優秀なので、E2EEでチャットを使うとき以外は利用する頻度が少なくなりました。
Show more

Response from developer

Thank you for taking the time to provide such detailed and valuable feedback. We'll make sure to share your review with the rest of our team so all of the points you mentioned can be taken into consideration for future improvements.

Font improvements

Glad to see I can make the font a legible size now—I look forward to using it and seeing how it differs from the competition

Response from developer

Thank you for your review. We've shared your request with the team for future consideration. You can follow our blog (https://proton.me/blog) and our direct channels for any news and updates.

Good for single shot prompt

Performing well and fast for single shot prompts, but for multiple shot prompt, it’s missing the flow. Previous instructions are getting diluted.

Response from developer

We're sorry to hear that. What exactly is happening on your side? If you are interested in further troubleshooting the issue, contact us via the contact form on our website so we can better help.

無料プランのレビュー

基本的な質問やったらまだマシや。でもほんまの仕事には全然使えへん。
データセットの根因分析やってくれって頼んだら、返事が一切来へんかった。猫のアイコンがずっと「考え中…」のままやったわ。そんで急にプレミアムのアップグレード押し出してきよった。
ChatGPT、Gemini、Claude、Qwenは無料でもちゃんと使える分析してくれるのに、Lumoはぐるぐる回って「金払え」ってせがんできよるだけや。
典型的な釣りやな、アップグレードさせるための。契約する気がないならほっとけ。

Response from developer

That doesn't sound right. Please contact us via the contact form on our website with more details and some screenshots so we can better help.

Sehr gut

Sehr ordentliche app. Schnell und zuverlässig. Etwas seltsam finde ich das die App versucht einem in eine Konversation zu verstricken indem relativ persönliche Fragen gestellt werden. Ansonsten sehr gelungen, weiter so!

Response from developer

Thank you for the feedback. Use the thumbs down button in order to report this so our team can further look into such reports and improve the service.

Brilliant

My experience has been excellent