HTML validation: is it worth it?
How important is to be W3C complaint. Currently I have 27 errors reported by W3C validator. Is that ok or I need to reduce the error count?
Your website may have errors, but it really depends upon the type of error.
Are they broken links? If they are, you should fix them as they may negatively impact your search engine ranking.
Are they DOCTYPE errors? The wrong DOCTYPE on your HTML can cause your website to render improperly in some browsers.
Are they general HTML/CSS errors? These can cause your website to display improperly as well as slow down the display of your website, as the browser may have to take extra time to figure out how to display the broken code.
Sometimes there are errors you just can't fix because they are out of your control. Ultimately, your goal would be to have no errors. It's not mission critical that you fix all the errors, but for an optimal user experience a no error site helps.