There is no such default role, but you can easily create a new role and explicitly deny the user to access the backend of the website. In this way he will not be able to edit the content of your website. I will log your request for having a default role for Frontend users. Thank you for suggesting this feature.
Excuse us for the late response, please let me know whether there is anything else we can do for you.
All the best,
the Telerik team
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