Delta Chat is a free open-source messenger for people who want private conversations without handing over a phone number.4 It is worth considering for a family or small group willing to try another chat app. Its default setup encrypts messages before they reach the servers carrying them.3
Last checked October 28, 2026.
At a glance
- What it is: A decentralized messenger with shared in-chat tools.4
- Works on: Android, iPhone/iPad, Windows, macOS and Linux.2
- Price: Free on the US App Store.8
- Licence: GPL-3.0-or-later for the desktop and Android clients.54
- Best for: Friends and families who value phone-number-free chat and a choice of server.
- Official site: delta.chat
What Delta Chat does and how it protects your privacy
Delta Chat uses chatmail relays: servers that pass messages between people, rather like sorting offices.3 End-to-end encryption means those relays cannot read the messages they carry.3 The default chatmail setup prevents sending or receiving unencrypted messages.1
New profiles use community-run relays and randomly generated addresses; an existing email account is unnecessary.3 You are not tied to one relay, and you can remove a relay or add another at any time.3 You can also use your own email address or server, according to the app’s store description.4 Start with the normal setup unless you have a particular reason to manage infrastructure.
Desktop version 2.65.0 was released on October 27, 2026, with pinned messages and a screen-reader fix.6 Version numbers can differ between platforms and distribution channels, so use the download route for your device.
Key features of Delta Chat
- No phone number: Start chatting without supplying one.4
- Several profiles: Keep different circles in separate chat identities.4
- Multiple devices: Use your profile across devices.4
- Shared tools: Add shopping lists, calendars or games to a conversation.4
- Encrypted attachments: Protection includes files and their filenames.1
- Independent desktop use: A phone installation is unnecessary.2
Delta Chat pros and cons
Pros
- Phone-number-free signup offers a useful separation from a phone account.
- Desktop apps can be used without a phone installation.
- Separate profiles keep different circles apart.
- A chat can hold a shopping list, a calendar or a game.
- The desktop source is published, and a 2024 cryptographic analysis is public.57
Cons
- Invitations take coordination: There is no public people search.1
- Delivery needs attention: Android background restrictions can delay incoming messages.1
- Encryption has limits: The FAQ says perfect forward secrecy is not yet supported. It says Autocrypt v2, scheduled for full implementation in 2026, will provide forward secrecy.1
- Desktop downloads vary: Some official download options have no automatic updates.2
Is Delta Chat safe and private?
F-Droid describes development as a community effort, and Apple’s listing identifies merlinux as the developer.48 The desktop repository publishes its code under GPL-3.0-or-later.5 An open-source licence lets others inspect and modify the software; it does not promise that bugs cannot exist.
The privacy policy says there are no ads or tracking, while Android usage statistics require agreement.3 Chats, contacts and encryption keys stay on devices. Relays delete messages after delivery, or typically after a few weeks.3 Keep device locks enabled and plan a recovery routine before moving important conversations. The Academy’s Duplicati guide is a related starting point when thinking about backups.
Encryption does not hide every connection detail. The privacy policy says a relay sees your random address, the size and randomized date of messages and, for connectivity, your IP address.3 An IP address identifies an internet connection, so a phone-number-free profile is still tied to the network you use.
ETH Zurich researchers reported five attacks in their 2024 analysis. The published abstract says the findings were disclosed to the Delta Chat team, who implemented fixes.7 That research concerns earlier software and is not a current certification of every feature. The FAQ says that if a private decryption key leaks, someone who collected earlier in-transit messages can decrypt them.1 People facing serious targeted threats should weigh that limitation carefully.
How to get started with Delta Chat
- Choose an official download. Open Delta Chat’s download page and select your platform.2 Prefer a route that makes keeping up with updates straightforward.
- Create a profile. Use the default chatmail setup, which supplies random relay addresses without asking for personal signup details.3 Choose a display name appropriate for the people you plan to contact.
- Connect with someone you know. Share the invitation privately or have your contact scan your QR code.1 Start with one willing friend.
- Send a small first message. Ask your friend to reply, then repeat with the phone locked. This gives you a practical delivery check before relying on the app.
- Consider another device. The documented route is Settings → Add Second Device, with both devices on the same Wi-Fi or network.1 Follow the prompts before retiring the original device.
Who should use Delta Chat, and who might prefer something else?
Delta Chat is a good candidate for a household, friendship group or club that wants to start small. Try an ordinary conversation first, agree how to invite others, and decide who will help less confident members.
Put Dino and Briar on your comparison list before moving an established group. Compare the devices your friends use, your need for dependable delivery, and the help available when something goes wrong. Avoid moving every conversation at once.
Frequently asked questions
Is Delta Chat free?
Yes. The US App Store lists the app as free.8
Does Delta Chat work on iPhone and on a computer?
Yes. The official download page covers iPhone/iPad, Windows, macOS and Linux, alongside Android.2
Do you need a phone number for Delta Chat?
No. Its published app description offers signup without a phone number.4
Can Delta Chat send ordinary unencrypted email?
The default setup requires encryption, but the privacy policy says unencrypted messages become possible only if you select a classic server and disable forced encryption.3 Keep the default for private chat. Changing that setting changes the protection you are choosing.
