CHT·14 · Chat & Assistants

Lumo

An AI assistant from Proton, the company behind Proton Mail, built with encrypted chat history and a promise not to train on your conversations.

PricingFreemium

CategoryChat & Assistants

Last checkedNov 2026

What is Lumo?

Lumo is Proton's AI assistant. It answers questions, helps with writing, summarises documents and can search the web, with privacy at the centre of its design.

Saved chats are encrypted so that only you can read them, and Proton says it does not use conversations to train models. It is a good fit for Proton users and anyone cautious about sharing data with AI services, though it offers fewer extras than the largest assistants.

Key features

Encrypted historySaved chats only you can read.

Document helpUpload files to summarise or ask about them.

Web searchOptional search for current information.

Proton integrationWorks with your Proton account and apps.

How to get started

Go to lumo.proton.me.
Start a chat with or without a Proton account.
Upload a document and ask for a summary.

Our take

A trustworthy pick for people who put privacy first.

Best for

Privacy-conscious users
Proton customers
Everyday writing and questions

Strengths

Encrypted chat history
No training on your chats

Limits

Fewer advanced features than leading assistants
Best features need Lumo Plus

Visit Lumo ↗

Questions

Is Lumo free?

Lumo has a free plan with usage limits. Paid plans unlock more usage and features.

What is Lumo best for?

Lumo is best for: Privacy-conscious users, Proton customers, and Everyday writing and questions.

What are the best alternatives to Lumo?

Popular alternatives in Chat & Assistants include ChatGPT, Claude, Gemini, Microsoft Copilot, and DeepSeek.

Pricing and features change often. Confirm details on the official Lumo website.