One thing I noticed as I visited other blogs during Blaugust is that while many have a favicon, some do not. There was a time that adding an icon to a WordPress required a lot of fiddling, or a theme that accepted one. But now days, it’s as easy as finding a square 512×512 image and uploading it to the blog.

WordPress.com calls these “Site Icons” and defines them as:

Site Icons are what you see in browser tabs, bookmark bars, and within the WordPress mobile apps.

Let me add to it that this also shows in some RSS readers and things like that, too.

Here’s the difference between a site with and without an icon:

As you can see, the one of the left just displays a WordPress icon. Which is fine. But to really personalize the way your blog displays to others in various places, you can change it.

Whether you’re on WordPress.com or self hosted, the location for this is the same (unless you have a self-hosted theme that works differently).

Follow the steps below to use Site Icon to set up a favicon for your site.
1 -Prepare the image file. (It must be square, having a height and width of at least 512 px.)
2- Navigate to Administration Screen > Appearance > Customize
3- Click Site Identity
4- Click Select Image (located under the Site Icon subheading).
5- Click on the Upload Files tab, then click Select Files to upload the image file that you prepared in the previous step.

Source

WordPress will give you a preview that looks something like this:

And there you have it – your WordPress blog now has a personalized favicon!