Just provide your original site logo (possibly simplified to best suit a favicon), optionally your main colors and your app name also, and this online tool will automatically generate the text to include in the head section and the package of all image sizes, including your site manifest, to upload to your root folder.
In less than 5 minutes in total you have your site favicon in all versions, free, no install and no registration = all what we like here. Kudos!
You can also inspect any URL regarding its favicon choices; very useful for comparison purposes
Privacy: we have no feedback of potential problem with this tool and author. But like many online services, you are here providing them with your own data. Depending of the criticity of your data, this is your responsibility to assess author's reputation and potential misusage, and to check and accept their terms and conditions, or not.
