The definition highlights how this graphic element can improve the interaction between the user and the reference site, but what are the ideal technical characteristics to make the most of its potential?
Technically, a favicon has a graphic size of 16x16 pixels, but it is not difficult to create one with larger dimensions, for example, 128x128 pixels, since the system used for its source code will appropriately resize the image.
Considering Microsoft's standards, you can also create favicons with sizes of 64x64, 32x32, and 24x24 pixels depending on where you need it to be more identifiable. Specifically, the optimal display of a favicon on Microsoft Edge is 16x16 pixels in the address bar, 32x32 pixels in new tabs, and 24x24 pixels in the browser bar.
An aspect you need to pay attention to is the reference extension; a favicon has an ICO extension, which is ideal for creating very small images. If your software for creating favicons does not have this extension, you can still use JPG and PNG formats, the latter being particularly suitable if you want to make changes later and subsequently convert to ICO format.