When you delete a message on Slack, whether someone can see it or not depends on a few factors.
First, if you delete a message in a direct message (DM) or a private channel, the other participants will not receive a notification that the message was deleted. However, they might notice that the message is missing if they had already seen it before you deleted it.
In public channels, the situation is similar. Other members of the channel will not get a specific notification that a message was deleted. But again, if they had already seen the message, they might notice its absence.
Here are some key points to consider:
- No notification: Slack does not send a notification to other users when a message is deleted.
- Visibility: If someone has already seen the message, they might notice it is gone.
- Audit logs: In some workspaces, especially those on paid plans, administrators can access audit logs. These logs can show message deletions, so admins might be able to see that a message was deleted.
In summary, while Slack does not directly notify users when a message is deleted, people might still notice if they had seen the message before.
Additionally, workspace administrators might have ways to see deleted messages through audit logs.