What are private chats and how can I use them?

Threema offers the following basic features for both single chats and group chats:

• Send text and voice messages
  
• Make voice and video calls
• Conduct group calls
• Share photos, videos, animated GIFs, and locations
  
• Send files of any type
  
• Use Threema on the desktop

Special features:

• Create polls
  
• Silently agree or disagree with received messages
  
• Hide confidential chats and password-protect them with a PIN or your fingerprint
  
• Use Threema Safe to anonymously backup your most important Threema data
• Choose between dark and light theme
  
• Use Threema on tablets and devices without a SIM card
  
• Verify your contacts via QR code
  
• Add text formatting to messages
  
• Create distribution lists^*
  
• Chat completely anonymously – no phone number required
  
• Contact sync is optional
• Quote text messages
• Pin chats
• Edit and delete sent messages on the recipient’s end
• Mark important messages with a star to find them without searching

Special features of the Threema Work app:

• Automatically disable notifications outside of working hours

^*) Currently only available in Threema for Android.

Threema allows to create a poll right inside a chat. No need to write back and forth when considering several options – initiate a poll with a few taps, and get a useful overview of the received votes.

• Android: In a chat, tap the paperclip icon, and select “Poll”
  
• iOS: In a chat, tap the plus sign next to the text-input field, and select “Create Poll”
  

Check out the promo video.

• In a single or group chat, tap and hold a received message to invoke the context menu
• To agree or disagree with the selected message, tap “agree / thumbs up” or “disagree / thumbs down,” respectively

In Threema, text can be formatted bold, italic, and crossed out. To format text, simply enclose it in the appropriate character:

• *bold*
• _italic_
• ~strikethrough~

This FAQ article covers the QR code that can be displayed in the app (and is used to confirm a contact’s identity and add their Threema ID at the same time; green verification level), not to be confused with the QR code on threema.id websites (which can only be used to add contacts; red verification level).

Scanning QR codes is a means for confirming contacts’ identities. That way, man-in-the-middle attacks can be effectively prevented: If you receive a message from a confirmed contact (i.e., verification level 3), you can be sure that it wasn’t spoofed or read by a third party (provided said contact’s device wasn’t stolen or hacked). On top of that, scanning someone’s QR code is a convenient way of adding them to your contact list without having to manually enter their ID.

Display your own QR code

• Navigate to the “My Profile” (Android) or “Profile” (iOS) tab and tap the QR code icon

Scan a contact’s QR code

• Android: in the Contacts tab, tap the “New contact” button, and select “Scan ID”
• iOS: Threema > Profile > QR-code icon in the top right corner

If you are having trouble scanning a QR code, please make sure the camera is not too close (below 10 in/25 cm), which might prevent it from focussing.

Android
Threema applies the system-wide font size settings (“Settings > Display > Display size and text > Font size”). If desired, it can also be adjusted directly in the Threema app: tap on the three vertical dots in the top right, select “Settings > Appearance > Font size,” and choose the desired option.

iOS
Threema applies the system-wide font size settings. Under iOS, they can be adjusted under “Settings > Display & Brightness > Text Size.” If desired, the font size can also be configured per app (as described in this support entry).

To save a chat outside of Threema, you can export it as an encrypted ZIP file (which will contain the chat as text file and, optionally, all media files). Please note that exported chats cannot be imported into Threema again; to transfer your chats to another device (or to restore them later on the current device), use a data backup. 

To export a chat, please proceed as follows:

• Android: In the chat list, tap and hold a chat, and then tap the “Share” button. You can save or send the chat as an encrypted ZIP file using your installed apps.
• iOS: In a chat’s detail view, tap “Export Chat.” (To open a chat’s detail view, open the chat and tap on the contact’s name.)

Chat exports are encrypted using the Advanced Encryption Standard (AES). Therefore, a modern file archiver, such as 7-Zip for Windows, is required to unpack a chat export. Some other apps don’t recognize the encryption and return an error message stating that the provided password is incorrect (even though you have entered the password correctly).

Use Threema to send files of any type (PDF, animated GIF, MP3, DOC, ZIP, etc.). Just like all other messages, files are end-to-end encrypted. The maximum file size is 100 MB (it might, however, not be possible to send large files on older devices due to insufficient memory). To avoid compression of an image or video, you can send it as a file. Please note: if you send an image as a file, its EXIF tags (possibly containing information such as the date and location the image was taken) are preserved.

Android: In a chat, tap on the paperclip icon, and select “File.”

iOS: In a chat, tap on the “+,” and select “Share File.” Due to restrictions of iOS regarding the file system, you can only access content of apps that support file sharing.

Threema is available in a light and a dark theme. You can switch between the two themes here:

Settings > Appearance > Design theme

To quote a text message, tap and hold it until the context menu appears. There, tap the quotation mark icon, and the quoted message will show up above the text input field. You can also swipe right to quote a message. Then, compose and send your message like you usually would. In the chat, the quoted message is indented and prepended to your new message so that it’s evident what you are referring to.

It’s not yet possible to use a Threema ID on multiple mobile devices at the same time. You can, however, use the desktop app or the web client to connect to the device on which your Threema ID is set up.

A multi-device solution that meets Threema’s strict security and privacy requirements is currently in development. iOS users already have the possibility to use the beta version of the upcoming desktop app, which can be used even if the associated iOS device happens to be offline.

If there are unresolved issues in a chat, you can use the “pin” feature to create a visual reminder. Pinned chats always stay on top of the chat list and are marked with a yellow pin icon:

• Android/iOS: In the chat overview, swipe from left to right on a chat and tap the pin icon to (un)pin the chat
  
• Desktop app / web client: Open the desired chat, and tap the pin icon in the top right corner to (un)pin it
  

In the chat overview, swipe from right to left on a chat to archive it (on iOS devices, you additionally have to tap on the gray button with the box icon). The chat will be removed from the chat overview, but not deleted. 

To access your archived chats, scroll to the end of the chat overview, and tap the button “X archived chats” (Android) or “Archived Chats” (iOS).

In order to move an archived chat from the archive back to the chat overview, proceed as follows:

• Android: Tap and hold the chat until the action icons appear in the title bar. There, tap the icon next to the trash-bin icon.
• iOS: Swipe left on a chat and tap on the gray button with the box icon.

To share your current location, open a chat, tap on the paperclip icon (Android) or the plus sign (iOS), and select “Location” (Android) or “Share Location” (iOS).

You can send GIFs just like you send other images: in a chat, tap the paperclip icon (Android) or the plus sign (iOS), and select the GIF you would like to send.

Another possibility to send GIFs is to copy them from an app or website and paste them in the text input field.

For privacy reasons, there’s no GIF platform integrated into Threema. However, users can, of course, use third-party GIF keyboards to retrieve GIFs directly in Threema.

Create a new group, but don’t add any contacts. Messages you send to that empty group chat will stay on your device and are not sent to the server. That’s ideal for securely storing notes, media, and documents, or transferring them to the desktop via web client.

As of Threema 5.5 for Android and Threema 6.2 for iOS, sent messages can be edited and deleted on the recipient’s end within the first six hours.

Edit Messages
To edit a sent message, please proceed as follows:

• Android: Tap and hold the message, select the pencil icon, and edit the message in the text-input field. To save the changes, tap the checkmark.
• iOS: Tap and hold the message, select “Edit,” and make the changes in the text-input field. To save the changes, tap the Send button.
• Threema 2.0 for desktop (beta): Move the mouse over the message and wait for the arrow to appear. Tap on it to open the context menu, and select “Edit.” Make the the changes in the text-input field, and click the Send button or press Enter to save the changes.

Once a message is updated, there’s an indication in the speech bubble to let the recipient know the message was edited, and in the message details, the edit history provides an overview of all the changes that have been made.

Delete Sent Messages
Within the first six hours, a message can be deleted on the recipient’s end:

• Android: Long-tap on the message until the context menu appears. Then, tap on the three dots in the top right corner, and select “Delete > Delete for everyone”
• iOS: Long-tap on the message until the context menu appears, select “Delete,” and choose “Delete for Everyone”

Instead of the message’s content, “This message has been deleted” will be displayed.