On Twitter, Google’s John Mueller said that it’s not necessary to block shared pieces of content on pages (headers, footers, etc.):
You don't need to block shared pieces of content on pages — that's a really common setup across the web.
— ? John ? (@JohnMu) May 17, 2019
How to find duplicate content on your web pages
It’s not a problem to use the same footer on all web pages. Duplicate content, however, can have a negative impact on the rankings of your web pages. The website audit tool in SEOprofiler helps you to find duplicate content on your website:
