So how many webpages don’t have a canonical tag set?
Based on our research and the data gathered from our site search health reports, we estimate that around 56% of web pages don’t have a canonical set.
This was a quick sampling of only 50 site search health reports, but there’s a clear pattern emerging — sites are either very good at setting their canonicals, or very bad.
We also don’t know how many of the sites have their canonicals set correctly until we start indexing and performing searches on their website. Just because they’re set doesn’t mean they’re necessarily doing the right thing — some websites have every canonical set to the homepage, which defeats the point of even having the tag set.