Lumo by Proton
Verified Oct 15, 2026 ActiveA privacy-focused AI chat assistant from Proton with zero-access encryption on conversations.
Listed on EffectHub ·
Pricing
- Pricing model
- Freemium
- Paid options from
- $9.99/mo
- Billing
- Monthly
Lumo Plus is $12.99 billed monthly, or about $9.99/month when billed annually; the free plan caps history, image generation, and projects.
Use tool ↗About Lumo by Proton
Lumo is Proton's AI chat assistant, built for answering questions, generating images, analyzing data, and working with documents while keeping conversations under zero-access encryption — meaning Proton itself cannot read them. It's made by Proton AG, the Swiss company behind Proton Mail, and is offered as a web app plus iOS and Android apps, with an option to connect through Tor for anonymous guest access without an account. The free plan limits Max-model usage, message and history length, and image generation to one project; Lumo Plus removes those caps for $12.99 a month, or about $9.99 a month billed annually.
- API
- Not confirmed
- Last verified
- Oct 15, 2026
Verified sources
- Describes Lumo's zero-access encryption, Proton AG as the maker, Tor guest access, and web/iOS/Android availabilityproton.me ↗
- Free vs Plus plan feature comparison on Proton's own pricing pageproton.me ↗
Is Lumo by Proton legit?
We don’t label tools safe or unsafe. Below are the records we checked ourselves, each with the date we read it.
- TLS certificate
- Issued by Let's Encrypt, valid until Dec 1, 2026Seen in our own connection to the site on Oct 15, 2026
- Last checked
- Oct 15, 2026The site answered
- Operated by
- Proton AG, SwitzerlandOur research, card verified Sep 1, 2026
Pros & cons of Lumo by Proton
Lumo's differentiator is genuinely structural rather than a marketing claim: Proton AG built its reputation on zero-access encrypted email and applies the same model here, plus a Tor option for account-free use. The free plan's limits on history and image generation are tight enough that regular users will likely need Plus fairly quickly.
Pros
- Zero-access encryption is a real architectural claim backed by Proton's existing email/VPN business, not new marketing copy
- Guest access over Tor works without any account at all
- Available on web, iOS, and Android rather than browser-only
Cons
- Free plan caps message history, image generation, and projects tightly enough to push regular users to Plus
- Annual billing ($9.99/mo) is meaningfully cheaper than the $12.99 monthly rate, which isn't obvious until checkout
Best for
- Users who already trust Proton's privacy model and want an AI chat under the same guarantees
- Anyone wanting to try AI chat anonymously via Tor without creating an account
Not for
- Users who need the single most capable model available regardless of privacy trade-offs
- Anyone wanting deep integration with non-Proton productivity tools
Alternatives to Lumo by Proton
Lumo by Proton head-to-head
Side-by-side fact sheets against the competitors our research or their makers name — pricing, platforms, API and both verdicts on one page.