I don’t think we have any such ranking of the best SEO friendly websites in the world. No research or study has happened on this.
So, it’s really difficult to answer your question; more so, given the fact that there are well over 1.9 billion websites in the world. (Check the total number of websites live)
But, let’s dig in deeper to this…
(i) Speed of the website: An SEO-optimized website loads very fast.
(ii) Number of quality backlinks: It has a good number of backlinks from other websites that have high domain authority and Page Rank.
(iii) Good contents: Search engines love websites with good, in-depth and updated contents.
(iiii) Mobile-friendliness: A website that performs well on mobile devices ranks higher on SERP.
(v) The technical stuff: There are many technical aspects to SEO—schema markup, AMP implementation, XML sitemap, crawl errors and more. A website must follow Google’s guidelines and suggestions strictly to ace the technical end.
As you can see, these 5 attributes are subjective and have many variables. For instance, how do you define “quality” in
quality backlinks? Or, what kind of content do you call“good”?
So, in short, it’s fairly difficult to count out the best SEO friendly websites in the world—because they depend on an awful lot of factors. And there would likely be many of them.
Sure, you can use SEO analyzers. But even they will rank the same websites differently—because each of them factors different parameters to rate SEO-friendliness of the website. Some would care more about the meta tags, other would obsess the backlinks more; so, their points/grades would vary.
So, again, it’s difficult to answer your question.
However, that being said, you can assume that the websites that rank at #1 on SERP are likely SEO friendly because they are ranking at the very top. (But note that this assumption is flawed because rankings of websites fluctuate even with NO change on-page.)
Also, it’s safe to assume that the websites who teach about SEO or offer SEO services, they have a fairly SEO-optimized websites. So, websites like HubSpot, Neil Patel, Moz, Ahref, Search Engine Journal and more are good in the SEO-end.
Here’s an SEO Analyzer. Analyze websites and see how search-friendly they are.