What is Delta Chat?

From the Delta Chat FAQ.

What is Delta Chat?

Delta Chat is a reliable, decentralized and secure instant messaging app, available for mobile and desktop platforms.

• Instant creation of private chat profiles with secure and interoperable chatmail relays that offer instant message delivery, and Push Notifications for iOS and Android devices.

• Pervasive multi-profile and multi-device support on all platforms and between different chatmail apps.

• Interactive in-chat apps for gaming and collaboration

• Audited end-to-end encryption safe against network and server attacks.

• Free and Open Source software, both app and server side, built on Internet Standards.

How can I find people to chat with?

First, note that Delta Chat is a private messenger. There is no public discovery, you decide about your contacts.

• If you are face to face with your friend or family, tap the QR Code icon on the main screen.
  Ask your chat partner to scan the QR image with their Delta Chat app.

• For a remote contact setup, from the same screen, click “Copy” or “Share” and send the invite link through another private chat.

Now wait while connection gets established.

• If both sides are online, they will soon see a chat and can start messaging securely.

• If one side is offline or in bad network, the ability to chat is delayed until connectivity is restored.

Congratulations! You now will automatically use end-to-end encryption with this contact. If you add each other to groups, end-to-end encryption will be established among all members.

Why is a chat marked as “Request”?

As being a private messenger, only friends and family you share your QR code or invite link with can write to you.

Your friends may share your contact with other friends, this appears as Request

• You need to accept the request before you can reply.

• You can also delete it if you don’t want to chat with them for now.

• If you delete a request, future messages from that contact will still appear as message request, so you can change your mind. If you really don’t want to receive messages from this person, consider blocking them.

How can I put two of my friends in contact with each other?

Attach the first contact to the chat of the second using Attachment Button → Contact. You can also add a little introduction message.

The second contact will receive a card then and can tap it to start chatting with the first contact.

What are profiles? How can I switch between them?

A profile is a name, a picture and some additional information for encrypting messages. A profile lives on your device(s) only and uses the server only to relay messages.

On first installation of Delta Chat a first profile is created.

Later, you can tap your profile image in the upper left corner to Add Profiles or to Switch Profiles.

You may want to use separate profiles for political, family or work related activities.

You may also wish to learn how to use the same profile on multiple devices.

Who sees my profile picture?

You can add a profile picture in your settings. If you write to your contacts or add them via QR code, they automatically see it as your profile picture.

For privacy reasons, no one sees your profile picture until you write a message to them.

Can I set a Bio/Status with Delta Chat?

Yes, you can do so under Settings → Profile → Bio. Once you sent a message to a contact, they will see it when they view your contact details.

What do Pinning, Muting and Archiving mean?

Use these tools to organize your chats and keep everything in its place:

• Pinned chats always stay atop of the chat list. You can use them to access your most loved chats quickly or temporarily to not forget about things.

• Mute chats if you do not want to get notifications for them. Muted chats stay in place and you can also pin a muted chat.

• Archive chats if you do not want to see them in your chat list any longer. They remain accessible above the chat list or via search and are marked by Archived

• When an archived chat gets a new message, unless muted, it will pop out of the archive and back into your chat list. Muted chats stay archived until you unarchive them manually.

To use the functions, long tap or right click a chat in the chat list.

How do “Saved Messages” work?

Saved Messages is a chat that you can use to easily remember and find messages.

• In any chat, long tap or right click a message and select Save

• Saved messages are marked by the symbol next to the timestamp

• Later, open the “Saved Messages” chat - and you will see the saved messages there. By tapping , you can go back to the original message in the original chat

• Finally, you can also use “Saved Messages” to take personal notes - open the chat, type something, add a photo or a voice message etc.

• As “Saved Message” are synced, they can become very handy for transferring data between devices

Messages stay saved even if they are edited or deleted - may it be by sender, by device cleanup or by disappearing messages of other chats.

What does the green dot mean?

You can sometimes see a green dot next to the avatar of a contact. It means they were recently seen by you in the last 10 minutes, e.g. because they messaged you or sent a read receipt.

So this is not a real time online status and others will as well not always see that you are “online”.

What do the ticks shown beside outgoing messages mean?

• One tick means that the message was sent successfully to the relay.

• Two ticks indicate your contact has read the message.

In groups the second tick means that at least one member has reported back having read the message.

You will only get the second tick if both you and one of the recipients who read the message has Settings → Chats → Read Receipts enabled.

Correct typos and delete messages after sending

• You can edit the text of your messages after sending. For that, long tap or right click the message and select Edit or .

• If you have sent a message accidentally, from the same menu, select Delete and then Delete for Everyone.

While edited messages will have the word “Edited” next to the timestamp, deleted messages will be removed without a marker in the chat. Notifications are not sent and there is no time limit.

Note, that the original message may still be received by chat members who could have already replied, forwarded, saved, screenshotted or otherwise copied the message.

How is media quality handled?

Images, videos, files, voice messages etc. can be sent using the Attach- or Voice Message buttons.

• By default, compression ensures fast, efficient delivery that respects everyone’s data limits and storage. This is ideal for everyday communication.

• In regions with worse connectivity, you can choose higher compression at Settings → Chats → Outgoing Media Quality.

• If you specifically need to send media in its original quality, use Attach → File in the chat. Please use this method sparingly, as sending original files will significantly increase data usage for you and all recipients in the chat.

How do disappearing messages work?

You can turn on “disappearing messages” in the settings of a chat, at the top right of the chat window, by selecting a time span between 5 minutes and 1 year.

Until the setting is turned off again, each chat member’s Delta Chat app takes care of deleting the messages after the selected time span. The time span begins when the receiver first sees the message in Delta Chat. The messages are deleted both, on the servers, and in the apps itself.

Note that you can rely on disappearing messages only as long as you trust your chat partners; malicious chat partners can take photos, or otherwise save, copy or forward messages before deletion.

Apart from that, if one chat partner uninstalls Delta Chat, the (anyway encrypted) messages may take longer to get deleted from their server.

What happens if I turn on “Delete Messages from Device”?

If you want to save storage on your device, you can choose to delete old messages automatically.

To turn it on, go to Settings → Chats → Delete Message from Device. You can set a timeframe between “after an hour” and “after a year”; this way, all messages will be deleted from your device as soon as they are older than that.

How can I delete my chat profile?

If you are using more than one chat profile, you can remove single ones in the top profile switcher menu (on Android and iOS), or in the sidebar with a right click (in the Desktop app). Chat profiles are only removed on the device where deletion was triggered. Chat profiles on other devices will continue to fully function.

If you use a single default chat profile you can simply uninstall the app. This will still automatically trigger deletion of all associated address data on the chatmail server. For more info, please refer to the respective page from your 3rd party chatmail server.