Deleting your chat history and comments on Slack depends on your team’s settings and what role you’re assigned.
If you’re assigned a role that allows you modify messages, that is it allows you edit messages, then you are good to go. This means you’ll either be the owner or you will require your Team owner to enable you. Once you meet any of the above criteria, deleting your chats history in Slack desktop app becomes very easily.
To delete your chats messages
– Hover over the message
you’d like to delete.
– Click the Show message
– Click Delete message.
Here is a shortcut to quickly delete your
most recent message from your keyboard:
Press the Up arrow key , delete
the text, and hit Enter.
Click Yes, delete this message (or press Enter again) to confirm.
To delete comments which is part of the History
1 Hover over the file that
has the comment for deleting.
2 Click the Comments button in the
top right corner. To expand all comments
and open the information pane.
3 Click Delete comment.
That is all. But remember once you delete this there is no recovery. If you wish to recover your chat in future consider backing them up.