How to Change Favicon

Change Favicon Magento 2 - Favicon is short for “favorite icon”, and refers to the little icon on the tab of each browser page. Depending on the browser, the favicon also appears in the address bar, just before the URL. Favicons are generally 16 x 16 pixels or 32 x 32 pixels in size. Magento accepts ICO, PNG, JPG, and SVG file types, although not all browsers support these formats. The most widely supported file format to use for a favicon is ICO. There are many free tools available online that you can use to generate an ICO image or convert an exiting image to the format.

You can change Favicon in Magento 2 by the following steps:

Step 1: Create a Favicon

Create a 16x16 or 32x32 graphic image of your logo, using the image editor of your choice.
(Optional) Use one of the available online tools to convert the file to the .ico format. Then, save the file to your computer.

Step 2: Upload the Favicon to Your Store

On the Admin sidebar, click on Stores. Then under Settings, choose Configuration.
In the panel on the left under General, choose Design.
Expand the HTML Head section. Then, do the following:

 * Click on Choose File. Then, find the favicon file that you prepared.
 * If you want to delete the current favicon, mark the Delete Image checkbox.

When complete, click on Save Config.

Step 3: Refresh the Cache

When prompting to refresh the cache, click the Cache Management link in the message at the top of the workspace.
In the list, mark the Page Cache checkbox that is marked “Invalidated.”
Set Actions to “Refresh.” Then, click on Submit.
To view the new favicon, return to your storefront and press F5 to refresh the browser.

Ref: Magento 2 User Guide

It comes to the end of tutorial: How to Change Favicon in Magento 2.