Compare Lumo by Proton vs Copy.ai vs Onyx

Side-by-side comparison of Lumo by Proton, Copy.ai, Onyx
FeatureLumo by ProtonCopy.aiOnyx
DescriptionLumo is Proton's AI assistant for questions, writing help, and file chats, built so your conversation history stays encrypted and private. A free plan lets anyone try it, and Plus adds unlimited chats for people who want privacy-first help every day.AI copywriting for marketing and salesA self-hosted AI chat and search platform that connects to your team's documents and apps. Built for: Small teams who want an AI assistant over their shared knowledge. Format: Self-hosted web app (Docker). License: Open-core: MIT, except ee/ directories (Onyx Enterprise License). Open source on GitHub (32,407 stars as of 2026-10-11).
PricingFree $0; Lumo Plus $12.99/mo monthly or $9.99/mo billed yearly ($119.88/yr)$49/monthFree and open source (open-core: some features are paid); self-hosting, model or API costs may apply
Main categoryChat assistantsWritingResearch and notes
WebsiteVisit Lumo by ProtonVisit Copy.aiVisit Onyx
Info last checkedOctober 17, 2026October 12, 2026October 13, 2026

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