How to delete all messages on Mac does not come like other devices. You may have to follow some unique but easy steps to achieve this. However, with Mac devices, the owner or operator needs to learn some steps on how to delete messages. 

Unlike iOS , there's no in-app method to delete chat history on Mac OS X , and although you can close a window, it doesn't remove all data, logs, caches, or associations with a particular chat, and those caches are still stored on Mac.

How to Delete All Messages on Mac?

Macs and gadgets support some complex messaging system that requires special attention. Therefore, it is necessary to learn how to delete all messages on Mac. The tendency for someone else to track your messages on a device you've abandoned is one of the main risks with this. Therefore, you may need to know how to delete all messages on Mac. 

This is where knowing how to delete all messages on Mac or iPhone regularly can help.

Steps to delete all messages on Mac:

Select one or more messages (including text messages, photos, videos, files, web links, audio messages, or emojis) in the transcript, then press Delete.

Delete all messages within a conversation: Choose Edit > Clear Transcript.

This keeps the conversation in your sidebar while removing all content from the transcript.

You can set how long to keep messages – Choose Messaging > Preferences, click General, then click the Message Retention pop-up menu and select an option.

Delete messages and conversations in Messages on Mac

Messages automatically saves your conversations, so when you turn off your Mac or start using another device, you can pick up where you left off. However, you can delete messages as well as entire conversations.

Deleting a Message:

In the Messages app  on your Mac, select the conversation you want.

Select one or more messages (they can be text messages, photos, videos, files, web links, audio messages, or emoticons) in  the transcript , press the Delete key, and then click Delete in the dialog box.

Note: When you delete a message, it moves to the "Recently Deleted" folder on your device, but not on anyone else's device. To delete a message for everyone, use the Unsend function.

Delete a Conversation:

In the Messages app  on your Mac, find the conversation you want.

To delete a conversation, do one of the following:

Delete an empty conversation: Move the pointer to an empty conversation and click the Close button.

Delete a conversation: Select a conversation, hold Ctrl and click. Then select Delete. If you're using a trackpad or Magic Mouse, you can also swipe left with two fingers on that conversation in the sidebar, then click the Delete button.

Tip: You can also delete multiple conversations at once. In the sidebar, select conversations, hold Ctrl and click; then select Delete.