Enabling anonymous access to a SharePoint site allows anonymous users and authenticated users (who have not been given access) to browse the site, including lists, libraries, folders within lists or libraries, list items, or documents that inherit their permissions from the SharePoint site.
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1) Open the SharePoint site for which you want to enable anonymous access.
2) Go to site settings under Settings Gear on the top right-hand corner of your page.
3) Click on site permissions under User and Permissions.
4) Click on Anonymous Access under Permissions tab.
5) A box will pop up as shown below: click OK.
And anonymous access will be enabled. Easily make your SharePoint site Internet facing.