Compare software

Delta Chat vs Session: catalog facts
Delta Chat	Session
Free Free and open source under the GPL 3.0. Free chatmail relays are provided, or use any…	Free Free and open source under the GPL 3.0, run by the Session Technology Foundation.
Windows, macOS, Linux, Android, iOS	Windows, macOS, Linux, Android, iOS
Works with any email account, or with a provided chatmail relay Reaches people who do not use Delta Chat at all	No phone number or email needed; the account is a random ID Onion routing hides your address from recipients and from the network
Encryption only applies when the other side supports Autocrypt Email metadata such as subject and timing is visible to mail servers	Losing your recovery phrase means losing the account with no reset Delivery can be slower than a centralised messenger
Downloadable app	Downloadable app
Open source	Open source
License: GPL-3.0	License: GPL-3.0
No account needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked September 21, 2026	Official website Full listing and sources Checked September 21, 2026

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