Delta Chat for iPhone

What Delta Chat provides

Delta Chat is a messaging app that runs over the global e-mail infrastructure, so you can message anyone with an e-mail address without routing conversations through a centralized chat server. It looks and feels like a modern chat app while functioning as a standard e-mail client beneath the surface.

How it functions

• It links to your existing e-mail account and sends messages as ordinary e-mails, letting recipients reply with any mail app.
• Conversations appear in a chat-style thread in the app, while each message is still an e-mail on the transport layer.
• Because it uses your mail provider, you can change phone numbers or use devices without a SIM card and still keep chatting.

Privacy and security

Delta Chat keeps your conversation and contact records locally on your devices rather than storing them on a company-controlled server. When both sides of a conversation support encryption, the app can negotiate end-to-end protection automatically so messages remain confidential between participants.

Messaging, attachments, and compatibility

• File, photo, and group messages are delivered as regular e-mail attachments, which means they remain compatible with standard mail clients.
• Contacts don’t need to install Delta Chat: anyone can receive messages as normal e-mails and reply from their preferred mail app.
• Group chats behave like multi-recipient e-mails, preserving interoperability with people who use conventional e-mail software.

Development approach and community

The Delta Chat project emphasizes usability and pragmatic design while accepting contributions from a diverse community. Volunteers and developers help by reporting issues, translating the interface, testing with different mail servers, and contributing code. The project supports multiple programming languages and is localized into many human languages.

Notable strengths

• Uses existing e-mail accounts so setup can be simple and familiar.
• No central servers that store your personal messages.
• Works across standard e-mail clients, enabling communication with users who don’t install the app.
• Automatic negotiation of end-to-end encryption when possible.
• Local storage of chats and contacts for greater user control.
• Active, open contributor community for improvements and translations.

Alternatives

• Rave Watch Party (free) — an example of a different kind of communication/entertainment app you might consider if you need shared media viewing rather than e-mail–based messaging.