In the conversation where you'd like to delete a message:
- Hover to the right of the message, to show the Down Arrow▼.
- Click the Down Arrow ▼.
- Click Delete for me, or Delete for everyone.
Delete for everyone is only possible for messages that you've sent. The message will be deleted on all of your devices and your contact's devices. Your contact will see the Trash icon in place of the deleted message.
Delete for everyone is supported from Wire versions: iOS 2.14, Android 2.14.275. Deletion will only take effect when your contacts' devices are online.