You’ve changed the favicon.ico for your website but browsers still show the old version?

Here is a solution:

In your HTML-code find and replace

   <html>
     <head>
     ...
      <link rel="icon" 
            href="/favicon.ico" 
            type="image/x-icon"/>
     ...
     </head>
     ...
   </html>

with

   <html>
     <head>
     ...
      <link rel="icon" 
            href="/favicon.ico?v=201902112029" <---- put a timestamp here
            type="image/x-icon"/>
     </head>                              
     ...
   </html>

and change the timestamp, every time you publish a new favicon.ico-file.

This is still the simplest way to force browsers to reload the icon. Using some kind of a web-framework, automating this step in a template should be easy. Some pseudo code looks like this

   <html>
     <head>
     ...
      <link rel="icon" 
            href="/favicon.ico?v=<%= buildtime_parameter() %> 
            type="image/x-icon"
      />
     ...                                  
     </head>                             
     ...
   </html>

Happy coding!