Crawlability is a robot’s ability to crawl a website, a prerequisite to indexing the site’s content, and by extension, impacts the ability of any of the content to rank in search engines.
Here are tutorials that help with website structure and improved navigation.
- Website Check-list
- General 301 Redirections
- 301 Redirect https to http or Viceversa
- Force A 404 or 410 Server Response
- Fix Canonical Issues
- Strip Unwanted Query String
- The robots.txt File for a WordPress Site and Other Considerations
- Meta Refresh Redirection when a 301 is impossible
- Method for mod_turkey
Ok, so what’s validation got to do with this set of tutorials? Well the idea behind the name of this page is tied to the original Google Site where this set of tutorials first appeared. That Google Site was a companion to a Google group dedicated to solving markup validation issues at first and them expanded to everything to do with crawlability.
Yes invalid markup can in some cases make a page not crawlable or some content not reachable, which can affect indexing. Invalid css can also result in unintentionally hidden content which can lead to penalties.
So it’s important to ensure code and css are valid as much as possible.
The w3c html validator: http://validator.w3.org
The w3c CSS validator: http://jigsaw.w3.org/css-validator/