Good URLs are: - Short over long. Consider removing useless words from the url like news.ycombinator.com/tips-for-designing-good-urls - Concise. To the point,

Good URLs are: - Short over long. Consider removing useless words from the url like news.ycombinator.com/tips-for-designing-good-urls - Concise. To the point, describe the page content from the url - Use lowercase. Generally the best idea, for sharing links and technical issues (Apache is case-sensitive sometimes) - Consistent. Stay consistent, make a style guide for URL's if necessary - Conscious of trailing slashes. Stick with trailing slashes or no trailing slashes. Redirect to preferred form. - Logical. Follow a logical structure, that follows the structure of the site. A good URL might read like a breadcrumb: site.com/category/product-name, this works for silo'ing your content. Other sites (such as news sites or without a category) might benefit more from the shortest url possible. - Using dashes for spaces. No underscores, + or %20 spaces. - Not using special chars. Consider replacing é with e and removing any non-alphabet non-number character like: ' " ( - Canonical. There should be only 1 unique URL in a search engines index with a page content. Use canonical or 301's or smart use of URL's to make sure this is the case. - Degradable. What happens if a user visits example.com/category/product-name/ and then removes the /product-name/ part? The URL-structure should allow for this and example.com/category/ should return content (preferably the category description) - Timeless. If you have an event and you set the date inside the URL, then after this date has passed, this URL gets less valuable. Either 301 these aged URL's to the current event URL, or make it so your URL's can be "re-used" for future events. Cool URLs don't change. - Optimized for search. Use a keyword tool, to find out what users might be searching for and use the relevant keywords inside your URL. Keyword in URL is a (minute) ranking factor. Bolded keywords in URLs help discoverability. - Not using excessive dynamic variables. These will confuse your users and search engines. - Flat over deep. Hiding content away in many subdirectories can hamper readability and search engine crawling. Avoid example.com/cat/subcat/subsubcat/widgets/green/second-hand/widget-deluxe/reviews - Extension agnostic. An URL ending in .php, .py, .xml, .htm etc. can be changed to another extension in the future, requiring an update or inconsistency in the URLs. - Not spammy. Good URL's don't repeat (slight variations of) keywords or (ab)use extensions like .font or .shoe - Not disclosing technology. There is little reason to add cgi-bin to your URLs (unless you want to confuse your competition). An extension to really avoid is the .exe extension (mapserv.exe?doc=15) - Non-traversable. When using document IDs all URL's can easily be scanned/traversed in a loop or manually. Including URL's not yet ready/or never meant for publication. - Secure. Not susceptible to injection, XSS etc. I'd say URLs are both for humans and machines.