Never leave an
HTML
error on your web page. Open and check your
website in different web browsers. Make sure
things are aligned well, there is no font
missing and colors are visible.

If your site has
HTML
errors, the
Search engine spider might not be
able to crawl properly. Also the usability
of your site will decrease. So it’s better
to keep a check on the code. Make it error
free.

Top 3
Reasons your code should be error free:

1. Search engine spiders won’t be
   able to
   crawl your site easily. They
   calculate page download time. So you
   might receive a lower  SEO score.
2. Browsers behave very different for
   single
   code. Check code for IE and a
   Firefox user might receive an error or
   might not be able to view the page at
   all. This can result into higher bounce
   rates.
3. You will get negative points, if you
   have
   broken links in your site. Also
   if the links lead to pages that does not
   exist at all.

Tip:
How to find broken links in your blog or
website

The best way
to check that your code is correct:

Make sure that your website or blog complies
to World
Wide Web Consortium (W3C)
standards and guidelines. W3C is the
organization which sets standards for
various internet technologies like HTML CSS
and others

To check a
page you can use

HTML Validator service

If you use
your own feed use

feed validation service

Also don’t
forget to check your CSS with

CSS validator