Sometimes I am lazy about the code quality of my own pages. If all the browsers are showing the page as expected and visitors are able to get my site content, I can live with some “not-valid” piece of code. But it’s me. When working for clients, I am always checking the validity of the code (and the site ata all). Everything must pass the standard validation tests. And speaking of standards, here is the list of the 5 test tools I am using (almost) every day:
This is the validator. If you never checked your site’s code against this validator — go and do it. It is not just a validation service, it’s a learning tool too. After fixing the same type of error several times, I tend to avoid the wrong code in future. In brief — this (and all) W3 Validators are the industry standard for testing against the industry standards
Use this validation service to check your Cascading Style Sheets (CSS) and (X)HTML documents with inline CSS.
If you publish RSS or Atom feeds (who doesn’t?) — you may want to test them with this service.
This is a validation service that will run the above listed tests from one place. Just go to the Unicorn page, fill in the site (or upload page) and click the “check” button to get all the recommendations in one place.
The last of the W3C validators I’ll list here is the mobile readiness checker. This is extremely useful for those who are building mobile versions of their sites (and with mobile being mainstream these days, that’s everybody and his dog).