If you have registered for a free Similarweb account, you can delete your account from the user details page.
Go to User Settings>Account.
Within User Details, click Delete Account. Select a reason and choose what you would like to delete.
Click Delete Account.
When finished, click Done.
Your account will be deleted immediately and you will be redirected to the Similarweb Homepage. In addition, you will be unsubscribed from all emails from Similarweb.