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ThreemaDelta Chat
Paid

A one-time purchase is required. Business plans are separate.

 Free

Free and open source under the GPL 3.0. Free chatmail relays are provided, or use any…

Windows, macOS, Linux, Android, iOS, Web Windows, macOS, Linux, Android, iOS
  • No phone number or email required; the ID is random
  • Apps are open source and the company is based in Switzerland
  • Works with any email account, or with a provided chatmail relay
  • Reaches people who do not use Delta Chat at all
  • A one-time purchase is required for each platform
  • Smaller user base than the mainstream encrypted messengers
  • Encryption only applies when the other side supports Autocrypt
  • Email metadata such as subject and timing is visible to mail servers
Downloadable app Downloadable app
Open source Open source
License: AGPL-3.0 License: GPL-3.0
Not stated if an account is needed No account needed
Not stated if it works offline Works offline

Checked September 22, 2026

Checked September 21, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.