Lifehacker: “When you hit the share button on social media apps such as Instagram, Facebook, or Threads, these sites tack on a tracker to the link you’re sharing. This tracker means that Instagram can tell who you’ve shared the link with, and it likely uses this information to further optimize its algorithm for ads. While the tech here is sneaky, it is easy to remove tracking information from these links….”
See also URL Clean – URLs copied from Google search results (such as links to PDFs) are more complicated than they need to be. This tool removes the unnecessary parts, leaving the page’s original URL.