Similar to the Question: #32733809, I want to prevent SEO from duplicated content.
I've a separate domain only for shortened URL (mainly for sharing purpose)
I plan to set the
rel=canonical in the HTML head and redirect to the long-version on request, identified through the unique content-id (similar how stackoverflow does).
Which URL should I advisedly point to, getting the highest potential in regard to SEO?
<link rel="canonical" href="https://www.mainpage.com/content/1012921/">
<link rel="canonical" href="https://www.mainpage.com/content/1012921/this-is-the-original-and-long-version/">
<link rel="canonical" href="https://sho.rt/yd8eEndSX/">
Content-id wont change, but Domain/TLD (even if not assumed to) could.
Shortend Domain/TLD won't never change.