Validating a html web page
Validating your code is simply comparing it to W3C standards.
However all things being equal I would think valid code better for search engines than invalid code.Vender specific prefixes such as -webkit and -moz will never validate by definition.That doesn’t mean you shouldn’t use those vendor specific prefixes.I’ve included some screenshots at the bottom of this post to show the full code I used to check under each doctype.You can click any of the 3 images for a larger and readable image.Some of those warnings aren’t going to be things you’ll want to fix.
Many tracking parameters you add to the end of a url will give a warning for example.
Let’s face it no one can really list every potential show stopping error where search engines are concerned.
The safest thing to do in that case is fix all your errors or as many as realistically possible.
If you click the links above it’ll look like they go to the same page, but I assure you they’re different.
Click the More Options link to see on each page to see.
There are plenty of browser extensions that will test the page you’re viewing in the W3C validators.