Olvid vs SimpleX Chat

Olvid is an instant messaging app for text messages and attachments, available on Android, iOS, Linux, macOS, web, and Windows. Olvid says it does not require identifying details such as a phone number, email, name, address, or birth date. It also says messages and metadata are end-to-end encrypted, so it cannot know who is communicating with whom. Each message and file uses a single-use ephemeral key, intended to protect message history if a key is compromised. The app supports synchronization across devices without a master device. Secure audio and video calls are end-to-end encrypted; video calls support up to two contacts, while group audio calls have no participant limit. Receiving calls is free, and initiating them is free during a one-month trial that ends without billing or automatic subscription. The free plan includes unlimited messages and attachments, group discussions, ephemeral messages, multiple profiles, and inbound calls. Business costs €990 a year; Enterprise costs €990.50 a year.

SimpleX Chat is a messaging application for the SimpleX platform, with apps for Android, iOS, Linux, macOS, and Windows. It supports encrypted text with Markdown and editing, media and file sharing, decentralized groups, voice messages, disappearing messages, and audio and video calls. The network does not assign profile identifiers such as phone numbers or usernames. Messages and metadata use end-to-end encryption with continuous post-quantum key exchange. Four servers participate in each chat so relay servers cannot see which IP addresses communicate. Profiles, contacts, and messages remain in a portable encrypted database on user devices; relay servers hold encrypted messages only until delivery. Users may operate their own servers and still reach people using preconfigured servers. Developers can build bots and integrations using protocol SDKs; the TypeScript SDK connects to the Chat CLI over a WebSocket API. A phone or tablet can link to the desktop app only when both devices share a local network. Disappearing messages and recipient-side deletion are not guaranteed when a recipient device is offline or modified. The free plan costs nothing.