When Proton announced Lumo, its privacy-first AI assistant, I was intrigued but skeptical.

Proton has built a reputation on offering secure, encrypted alternatives to Gmail, Google Drive, and even a password manager.

But could the company really deliver an AI assistant that competes with ChatGPT or Google Gemini without hoarding my data?

I decided to find out the only way I know how: by using it for everyday tasks.

Over the past week, I swapped out ChatGPT for Lumo to see how it handled my mix of work, planning, and random late-night questions on my phone.

Lumo: The privacy-first AI

The app looks promising

Before diving into my experiments, it is worth noting how Lumo differs from other AI assistants.

Proton’s entire ecosystem is built on zero-access encryption and data protection laws in Switzerland, which means they cannot peek at your emails, notes, or prompts.

With Lumo, the philosophy carries over. It does not use my chats to train the model, and my requests are not sold to advertisers or logged for personalization. That already felt like a relief.

I have had moments in the past where I wanted to ask ChatGPT sensitive, personal queries. However, I didn’t because I felt uneasy about where that data might end up.

With Lumo, the pitch is simple: get an AI assistant without the surveillance baggage. But does that mean giving up usefulness?

How I tested Proton’s Lumo

Pitting it against ChatGPT

To see if a privacy-first assistant could hold its own, I used it in the same way I rely on ChatGPT every day. That meant asking it to draft quick emails, summarize articles I opened on my phone, and plan my weekly shopping list.

I wasn’t interested in running technical stress tests. What mattered to me was whether it could slot naturally into my workflow without slowing me down.

Over the course of a week, I swapped out my usual assistant for Proton’s Lumo and kept track of when it shone, when it stumbled, and when I found myself tempted to go back to ChatGPT.

Task 1: Researching a topic

Putting Lumo’s fact-finding skills to the test

One of the main ways I rely on an assistant is for research, whether that involves gathering background on a new tech trend or unpacking something more practical.

So, I gave Proton’s Lumo the same challenge I’d usually hand to ChatGPT: Summarize the pros and cons of using my phone as an offline e-reader.

By default, Lumo derives answers from its built-in knowledge base. That works well for evergreen questions, but if you want it to pull in the latest details, you have to turn on web search.

When I did, it pulled together concise, sourced summaries I could skim in under a minute.

However, I noticed that Lumo wasn’t as creative or expansive when it came to exploring tangents.

Where ChatGPT might throw out quirky hacks or unexpected angles, Lumo leaned more on fact-based responses. It was great for accuracy, but sometimes it felt like I was missing that extra spark of ideas.

Task 2: Drafting messages

Polishing messages without the stress

To keep things practical, I tried Lumo on the kinds of writing tasks I usually juggle in a day, like replying to emails, drafting quick messages, and polishing notes.

Lumo was surprisingly good at cutting through the clutter. If my draft message was rambling or overly long, it trimmed it down without losing the tone. When I asked it to rephrase something more politely, it nailed the balance.

Where it felt limited was creativity.

If I wanted a witty touch or something a little more playful, the suggestions landed a bit flat compared to what ChatGPT might come up with. Lumo stuck close to clear, neutral phrasing.

It’s great for professional notes or quick texts, less so when I want personality to shine through.

Task 3: Creative brainstorming

Sparking new ideas

I wanted to see if Lumo could go beyond routine tasks and help me with creative ideas.

For instance, I asked it for mini home improvement projects I could tackle over a weekend. It suggested practical, doable ideas, like creating a floating shelf, organizing a cluttered drawer with labeled boxes, or adding simple lighting tweaks to brighten a room.

Lumo’s suggestions were always feasible and immediately usable, but it didn’t generate the wildly offbeat ideas that sometimes come when you’re brainstorming.

That makes it reliable for realistic planning, though less ideal if you’re looking for out-of-the-box inspiration.

Task 4: Privacy-sensitive queries

When confidentiality matters

One area where Lumo really stood out was handling sensitive queries. These are the questions or tasks I’d usually hesitate to give to ChatGPT or other cloud-based assistants.

It includes prompts for summarizing personal notes or drafting messages that mention sensitive information.

With Lumo, I could ask it to help without worrying about data being logged or shared.

For example, I tested it by asking Lumo for a summary of a confidential email thread and for suggestions on rephrasing sensitive updates to a colleague.

It processed everything on-device, and since chats are zero-access encrypted, my information never left my phone.

Compared to ChatGPT, which operates in the cloud and could theoretically store data (depending on settings), Lumo felt safer for everyday tasks that involve personal or sensitive information.

Where Lumo shines, and where it doesn’t

It’s reliable, with a few caveats

After trying Lumo for daily tasks, the strengths were clear: it handles privacy-sensitive tasks well and organizes responses cleanly.

The limitations are notable, too. It can’t always fetch real-time info unless I turn on web search. It also leans toward safe, neutral suggestions over creative flair, and it struggles to maintain context across long, ongoing projects.

Another downside is that chat history is limited to seven days unless you upgrade to Lumo Plus, a separate subscription that Proton’s Unlimited plan doesn’t include.

Privacy first, convenience close second

For privacy-conscious users, Lumo lives up to its promise. It can handle sensitive notes, messages, and day-to-day tasks reliably.

But it has its limits. Real-time updates, extended chat history, and playful creativity aren’t its strong suits. If those matter most, ChatGPT or other cloud-based assistants still have the edge.

For anyone prioritizing privacy without sacrificing basic productivity, Lumo is a capable companion. It may not wow you with groundbreaking ideas, but it keeps your daily tasks on track without compromising your data.