Here’s one way to change the favicon for your 2013 public site by editing a master page. The same technique can also be used to edit other elements.Create A Favicon.
First upload a favicon image to an anonymously accessible library (the 2010 image lib or 2013 site assets lib should work).
A favicon can be any image but should be square: 16 x 16 or 32 x 32 would be ideal. It should also be saved as favicon.ico – rename it if you use a jpg or png.
TIP: Some browsers (notably IE) may not show the image if it isn’t converted to an ico file at a site like: http://www.favicon.cc/
Adjust the Master Page.
Open the public site’s settings: domain.com/_layouts/15/settings.aspx
Download the desired master page from web designer galleries»master page and page layouts
RENAME the file to say”oslo1.master” (important!)
Open it in notepad or other text editor and change the image url in this line to your favicon’s url – it’s somewhere around line 21 in the Oslo master page: SharePoint:SPShortcutIcon runat=”server” IconUrl=”domain.com/siteimages/favicon.ico”
Deploy The Master Page.
Upload it back to the gallery and publish it
In settings go to Look and feel»master page
Select your new master from the 2 drop downs.
Using Sharepoint Designer
If you’re comfortable with SPD, you can avoid the download routine and edit the html master page directly. Just open the site in SPd and go to all files » catalogs » master pages and look for the correct html master to edit.
An example of the effect can be seen here: http://365new.webbrewers.com/
Visit my forum » if you have any questions. For development work, you can contact me here ». And if you think this would be useful to others, feel free to share it by clicking one of the share buttons up top!