Lumo
AI chat assistant with encrypted chat history, run on Proton servers in Europe.
- Swiss CompanyThe operating company is headquartered and legally incorporated in Switzerland.
- Swiss OwnedThe ultimate controlling owner is Swiss (Swiss persons, companies, foundations or public bodies).
- Free PlanA permanently free plan is available (not just a trial).
lumo.proton.me
Overview
Lumo is an AI chat assistant launched by Proton in July 2025. Proton lists the models currently in use as Qwen 3.5, GLM 5.3 and Apertus 1.5, the open model from EPFL, ETH Zurich and the Swiss National Supercomputing Centre, plus separate image models. The models run on Proton-controlled servers rather than through third-party AI APIs; when web search is enabled, simplified queries are sent to partner search APIs. Version 2.0 (June 2026) added image generation and recognition and a memory feature.
Lumo can be used without an account, with limits on messages and model usage. Saved chats require a Proton account and are stored with zero-access encryption; Proton states it keeps no logs of conversations and does not use them for model training. Prompts are decrypted on Lumo’s GPU servers for processing, so the service is not end-to-end encrypted in the sense of hiding content from the server. Lumo Plus raises usage limits, and Proton’s business plans include Lumo for Business.
Unlike Proton’s other services, Lumo is not hosted in Switzerland: Proton chose Germany and Norway for its servers in response to the proposed revision of the Swiss surveillance ordinance. The service is operated by Proton AG under Swiss law.
Why it may be a Swiss alternative
Lumo is operated by Proton AG, which is headquartered in Plan-les-Ouates, Geneva. Swiss-headquartered, Swiss-owned company; product developed (wholly or largely) in Switzerland.
Note: although the company is Swiss, customer data is not hosted in Switzerland.
May replace
- ChatGPTOpenAI · USRuns open-weight models (such as Qwen, GLM and Apertus) rather than OpenAI's own models.
- Google GeminiGoogle LLC · USCovers the standalone chat assistant, not the Google Workspace integration.
- Microsoft CopilotMicrosoft Corporation · USCovers the standalone chat assistant, not the Microsoft 365 integration.
Foreign products with overlapping functionality. An alternative is not necessarily a one-to-one replacement.
Swiss footprint
Five independent questions. A Swiss company is not automatically Swiss-hosted — and vice versa. How the footprint is assessed
Swiss native. Swiss-headquartered, Swiss-owned company; product developed (wholly or largely) in Switzerland.
- HeadquartersIs the operating company headquartered in Switzerland?
- Plan-les-Ouates, Geneva (GE), SwitzerlandVerified[1]
- Legal jurisdiction
- OwnershipIs the company ultimately Swiss-owned?
- Yes — Proton Foundation (Fondation Proton) · SwitzerlandVendor claim[4]
Proton states that the non-profit Proton Foundation is the primary shareholder of Proton AG; since June 2024 it has been the largest voting shareholder, endowed with shares donated by co-founders Andy Yen and Jason Stockman and first employee Dingchao Lu. The foundation is registered in Plan-les-Ouates (Fondation Proton, CHE-418.863.304). Employees hold most of the remaining shares; smaller stakes are held by the Geneva non-profit FONGIT and by Proton users. Proton says it has no venture capital investors. Exact percentages are not published.
- DevelopmentIs the product developed in Switzerland?
- PartlyInferred[5]
Developed by Proton AG, headquartered near Geneva. Proton's privacy policy also lists subsidiaries in North Macedonia and Taiwan as processors, and Proton runs an R&D office in Vilnius. Proton does not publish how development work is split between locations.
- HostingIs customer data hosted in Switzerland?
- No — Germany and NorwayVendor claim[1]
Proton's launch post (July 2025) says Lumo operates from Proton's European data centres and is the first product moved as Proton shifts most of its physical infrastructure out of Switzerland, citing the proposed revision of the Swiss surveillance ordinance (VÜPF/OSCPT). CEO Andy Yen told the Keystone-SDA news agency in July 2025 that Germany was chosen for Lumo's servers instead of Switzerland, with further capacity being built in Norway. Proton's current Lumo pages state only that Lumo runs on servers controlled entirely by Proton in Europe and give no per-country breakdown. The operator and contracting entity remain Proton AG under Swiss law.
- InfrastructureIs the hosting infrastructure operated by a Swiss-owned provider?
- Yes — Proton AG (Proton-controlled servers in third-party data centres) · SwitzerlandInferred[9]
Inferred from Proton's statement that Lumo runs on servers it controls in Europe and from an August 2026 watson.ch report that Proton rents secured space from data-centre operators rather than running its own data centres.
Features & platforms
- Platforms
- Deployment
- Made for
- Interface languages
- Launched
- 2025
Privacy & security
- End-to-end encryption
- Partly
- Encryption at rest
- Yes
- Encryption in transit
- Yes
- Multi-factor authentication
- Yes
- Not verified
- Single sign-on (SAML/OIDC), SCIM provisioning, Public API and Data export
- Certifications
- None listed
Pricing
Paid plans fromUSD 12.99 / monthLumo Plus, billed monthly (USD 119.88 per year billed annually); CHF and EUR prices also offered
- Pricing model
- Freemium
- Free plan
- Yes
- Free trial
- Unknown / not verified
- Enterprise plan
- Unknown / not verified
- Billing in CHF
- Yes
Prices checked 15 Oct 2026. Always confirm on the vendor’s site. Pricing page ↗
Open source
- Open source
- PartlyVerified[15]
The Android and iOS apps and the web client (in the ProtonMail/WebClients repository) are published under GPL-3.0. The server-side code is not published; the language models are open-weight models from third parties.
- Licence
- GPL-3.0 · OSI-approved licence
- Source code
- github.com/ProtonLumo
- GitHub
- 2 public repositories
- last commit
Statistics from GitHub, fetched 15 Oct 2026.
Company
Company based in Plan-les-Ouates near Geneva that develops encrypted email, calendar, cloud storage, password manager, VPN and AI assistant services. Its primary shareholder is the non-profit Proton Foundation.
More from Proton
- Proton Calendar — Calendars
- Proton Drive — Cloud Storage
- Proton Mail — Email
- Proton Pass — Password Managers
- Proton VPN — VPN
Similar Swiss products
AI assistant running open-weight models on Infomaniak's Swiss infrastructure.
Swiss native
- Hosted in Switzerland
- Free Plan
AI AssistantsFreemiumAI platform with internal GPT, document search, meeting minutes and chatbots.
Swiss company
- Hosted in Switzerland
- Self-hostable
AI AssistantsPaidAI assistant platform for regulated sectors, running open-source models in Switzerland.
Swiss company
- Hosted in Switzerland
AI AssistantsPaid
Sources & verification
Every claim on this page is marked as verified, vendor claim or inferred. Unknown means we could not confirm it — not that the answer is “no”.
- Verified Confirmed by an independent or official source such as the commercial register.
- Vendor claim Stated by the vendor in its own documentation, website or legal terms.
- Inferred Derived by the editors from indirect evidence — see the note.
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
- [13]
- [14]
- [15]
Proton AG
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]