Why do you need to validate your site on W3C?

To remove all html errors from your website. It make your website seo friendly.

To make your websites error free from HTML validation, Broken links, CSS error and all.

To make your website error free you need to validate your site on W3C?

You Don't - - - If you use other methods that produce visitors that work, you can save yourself all the headaches.

It should also be noted that a website which is not based on W3C standards may suffer the consequences of poor formatting resulting in less readability amongst the audience.

To confirm the website is error-free or not w3c validator is best tool

W3C validation is a process of analyzing the codes of the website in order to check if it conforms to the formatting standards. However, it should also be noted that a website which is not based on W3C standards may suffer the consequences of poor formatting resulting in less readability amongst the audience.
Here are some key reasons why W3C validation is essentially done:
Escalates Ranking on SERP’s
Improved User Experience
Ensures Multi-browser Compatible Site
Validation Works As A Debuggin

Check the coding errors on the website.

To check the coding errors in the website.

So that website can perform well online and easy to available on search engine.