What is the most common fix for duplicate content?

There are four methods of solving the problem, in order of preference:

  1. Not creating duplicate content.
  2. Redirecting duplicate content to the canonical URL.
  3. Adding a canonical link element to the duplicate page.
  4. Adding an HTML link from the duplicate page to the canonical page.

For More Information Please Refer: https://yoast.com/duplicate-content/