Google Will Usually Drop Session IDs from URLs
Instead of choosing a representative URL for a set of URLs with session IDs, Google will usually drop the session ID from the URLs completely if it recognises that they don’t return any unique content.
Removing a Folder Containing Multiple URLs in the URL Removal Tool Considered as a Single Request
Removing a folder containing multiple pages using the URL removal tool will be considered as a single removal request by Google. As there is a limit to the number of requests you can make with the removal tool, John recommends narrowing down to a specific folder or URL structure, as it will save you from having to individually request removals.
Performing URL Rewriting is the Best Way to Change the URL Structure of a Site
If you are changing the URL structure of a website, John recommends keeping the old URLs and rewriting the URLs on the server-side, if possible. This is because, from Google’s point of view, there is very little change and it’s easier to understand the content than having to reprocess all of the new URLs. If you are not able to keep the old URLs, ensure you 301 redirect from the old ones to the new ones. A redirect is a much stronger signal that you are moving content to new URLs than canonicalising them.
Google Treats Escaped & Unescaped Versions of URLs & Links as Equivalent
Escaped versions of URLs and links are treated exactly the same as the unescaped versions by Google.
Google Can Treat Hash URLs as Separate URLs if They Lead to Unique Content
Google usually ignores anything after the hash, but the exceptions to this are hashbang URLs and hash URLs that lead to unique content that isn’t available on the non-hash version of the URL. John recommends that you should avoid relying on this, however.
Keep URLs Under 1,000 Characters in Length
John recommends making sure that URLs are under 1,000 characters in length so that they can be crawled and indexed.
Google Will Read the URL String Contained After the Query Parameter
If you are using a ? query parameter, Google will read the remaining URL string and it is not something which blocks crawling or indexing. However, they will drop anything following a # parameter.
Be Consistent in Trailing Slash Usage Across a Site
John recommends being as consistent as possible with the use of the trailing slash in the links across a site.
There Are No SEO Benefits For Translated URLs
As long as Google is able to see unique URLs for each language, it is not a requirement for each word within the URL to be translated. While it can be positive for user experience, it doesn’t provide any SEO benefits.