Lumo by Proton

Name: Lumo by Proton
Availability: InStock
Rating: 3.4257426261901855 (3111 reviews)
Author: Proton AG

Proton AG

In-app purchases

3.11K reviews

PEGI 3

100K+

Downloads

PEGI 3

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About this app

"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 documents 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"

A private AI assistant by Proton

Updated on

Oct 1, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.

No data shared with third parties
Learn more about how developers declare sharing
This app may collect these data types
Personal info, App activity, and App info and performance
Data is encrypted in transit
You can request that data be deleted

Ratings and reviews

2.94K reviews

Temitope Awofeso

July 9, 2026

Lumo app not loading on Android! I am presently subscribed to Proton Unlimite which gives me access to other products. I was really happy to see that they have developed their own AI platform. Unfortunately, it does not reload after closing the app window (Yes, page comes up blank). This is frustrating. I had to uninstall and reinstall 3 times. The only work around is adding the web URL to my mobile homescreen I won't upgrade until the app is sorted. Overall, its a "Level headed" LLM AI.

4 people found this review helpful

Proton AG

July 9, 2026

That doesn't sound right. Could you share more details about the issue? Are you receiving any specific error messages when trying to run Lumo? Do you have any antivirus or firewall software installed on your device? Have you tried reinstalling the Lumo app? Contact us using the contact form on our website so we can help.

Ridge

July 4, 2026

Full rewrite cos I really wanna love it. Reminiscent of GPT-4, the info it collates is really good and follows instructions well. But the 7 day chat limit is killing me rn, even having it go into archive mode so I can't respond would be better so I don't lose access to the info. The sandglass icon comes up at like 5 days so I never know when it's actually gonna disappear. Also whilst selecting text, when you need to scroll, it'll select EVERYTHING so it's very hard to copy and paste on mobile.

6 people found this review helpful

Proton AG

June 25, 2026

Thank you for the review. With the free plan, chats are saved for a maximum of 7 days from the moment they were created. You may consider upgrading to Lumo Plus for extended chat history. On another note, our team is aware of the issue with chats disappearing, and they're working on a fix. Make sure to keep the app up-to-date for any improvements.

Lexi Willis

July 23, 2025

It's okay but I'm somewhat disappointed that this is just a frame of the web version. It can't generate images and you can't directly send photos from your camera without going into your camera app, taking a photo, opening Lumo again, opening the selection menu, and finding the photo. Right now it's very barebones and I wouldn't recommend it. Please Proton, make this review outdated.

52 people found this review helpful

Proton AG

July 24, 2025

Thank you for your review. Lumo’s capabilities are currently focused on text-based files, although we’re working on the ability to upload and analyze more file types, such as photos, in the future. Make sure to follow our blog (https://proton.me/blog) and our direct channels for any news and updates.