Kontalk vs Olvid

Kontalk has no write-up on Specifiction yet; its figures are above.

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.