Since i am trying to learn about creating websites i understand that this extension effects me much and i lose time for fixing errors so i want to know if i must care of it or not.It simply shows validation results about a page i visit/ built and when i see an error icon it makes me sick and i try to find ways to get rid of that errors.Its not hard much to not have errors if i create a page but problems/errors starts if i wanna use a third party code.Since the pages/sites rank well in serps even if it shows 263 errors + 20 warnings (for ex. Yahoo) i need to hear pro advices about if using/care this reports is good or not.
Thanks for any inputs
[edited by: encyclo at 6:59 pm (utc) on May 12, 2007] [edit reason] fixed link [/edit]
A lot of HTML errors are created in a "cascade" as one error high in the document makes the rest of the markup invalid - so often if you if the first instances of an error, many of the others will disappear in turn with no intervention.
In terms of search engine ranking, valid HTML in itself is not vital, but invalid HTML can cause parsing errors and reduce the potential of the content to rank well. Valid markup has many other advantages too - it makes you more aware of your document structure and how you should best optimize your markup, and it makes it much easier to debug problems with layouts. The last part is vital - if the page layout is broken, it becomes impossible to tell where the problem lies, as invalid markup can make the layout break in many different ways, and each browser can handle invalid markup differently.