I just checked my site with W3 CSS Validation Service. It had more than 200 errors.

Then I checked many sites including Stack OverFlow. Here is the results of Stack OverFlow. SO also has 108 errors.

Seems like SO also ignored it. What should I do? If we ignore it, will it affect to SEO wise? I mean a problem like Google can't properly read our website, etc.

  • Although slightly different since you're referencing Stack Overflow as a comparison, this question is highly similar: Does Google consider W3C validation errors of a website? If so why www.google.com has 23 Errors, 4 warning(s). The answers there might be helpful too.
    – dan
    Sep 25, 2017 at 6:17
  • Don't chase your tail later when parts of your site don't work cause browsers or standards change. Don't follow fools who ignore error checking (validation). Browsers are required to do the best they can with what errors you give them. Do you want browsers to guess at your intentions? Or do you want them to do what you tell them to do?
    – Rob
    Sep 26, 2017 at 12:04

2 Answers 2


W3C errors (css or html) increase the chances of your site not rendering correctly across all devices.

You should worry about the css errors and get them fixed.

There is an awesome W3C Validator Chrome plugin that makes troubleshooting easy.

  • 1
    THIS is the answer that should be upvoted and accepted! Nothing less. Anything else is an embarrassment.
    – Rob
    Sep 26, 2017 at 12:01
  • 1
    Rob, I want to buy you a beer. W3C Validation Errors are Web Design 101.
    – Andy Muns
    Sep 27, 2017 at 0:13
  • 1
    Too late. I'm already wasted.
    – Rob
    Sep 27, 2017 at 0:59

I would say it's good to have valid scripts. Having said that when you use third-party products it may be hard make it a valid one.

If you have a custom-designed solution then you can easily fix and make it fully valid.

So, i would say don't worry too much but if it is within your capacity to make it valid then go ahead and make one.


As stated, it's good to have valid HTML and CSS as it makes it easier to manage. But if you are using a third-party system and if it is too hard to make it a valid one the do not worry as search engine reads incorrect markup fine.

Watch This: https://www.youtube.com/watch?v=j3KgrbiB1pc

  • This is horrid advice and needs to be ignored, not accepted as an answer or upvoted!! The validation service is error checking and errors are NEVER a good thing and one should be fired for suggesting not to worry about it! Otherwise you have markup that "works" with no guarantees it will always work everywhere and that changes to the standard or to browsers will let your markup work everywhere, always.
    – Rob
    Sep 26, 2017 at 11:59
  • Are you really serious??? Firstly minor HTML validation errors are not like programming errors. Give me any 5 good third-party system which may have valid HTML and CSS. Be real and recommend right things. Its always good to have valid markup but in many situations its simply had and not even worth trying as they are not as major when it will break the system.
    – TopQnA
    Sep 26, 2017 at 12:53
  • As my mother said, if everyone jumped off a cliff, would you do the same? Errors are errors and to claim some errors are acceptable in any condition is beyond comprehension in any professional environment. I would fire anyone who said such a thing on the spot and immediately.
    – Rob
    Sep 26, 2017 at 12:55
  • You are entitled to your opinion. One line: Be real. Share any 5 examples popular products which may have valid markup. As stated its good to have valid markup if it can be done but it's very hard while using third-party systems. I am repeating what i said in the answer.
    – TopQnA
    Sep 26, 2017 at 13:05
  • 1
    I am talking holistic and real mate. So get real. Most of my own custom implementations have valid HTML etc. I have got some this party system and they don't have valid markup. Would I care? No. The question itself is about SEO. Read, understand and then comment.
    – TopQnA
    Sep 26, 2017 at 14:01

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