Forum Moderators: Robert Charlton & goodroi
Look at their homepage - [google.com...] , non Doctype declaration (which is important for various reasons [webmasterworld.com]), no validation e.t.c
Reason (by Matt)
"Google’s home page doesn’t validate and that’s mostly by design to save precious bytes. Will the world end because Google doesn’t put quotes around color attributes? No, and it makes the page load faster. :)
So should we care about HTML validation and doctype then?
If I can validate the whole page locally using better tools then why do I need width="140" when i can use width=140? every character space costs. Google is very good at that, their pages are not validated to keep it light. If I can check the google anaytics and test in all the browsers then why Doc type declaration as well?
Validation also helps with accessibility issues, too.
It's a good idea to try and get your sites to validate, for several reasons; good for visitors (as above), good because you learn while doing it, good because you'll likely end up with a leaner, meaner site which the SEs will better process, good because the effort will uncover problems you never knew existed, which could be important.
How obsessively you validate is a personal decision - there are other things to worry about as well, and 'validation sites' can be very time consuming and excessively fussy and webmaster-unfriendly.
Which brings us back to the original question; Does Google care?
No. But for all the reasons above, a site you have attempted to validate will have almost certainly have SEO advantages over a site where you never looked under the hood.
When I said "Does Google Care?" I meant to refer "Google as a top techy and visitor friendly company" not as "Google the SE". Google is not validating its code to save precious bytes.
Just as I suggested that Google doesn't 'care' if we validate (or not), I'd suggest there's no reason for us to care if they do (or not); what matters is not that they validate / don't validate, but that their site is accessible, functional and user-friendly.
If those 'real world' needs are satisfied, then it only matters if you seek a stick; to beat them with ;) if they fail to meeet those needs - it matters, but it's not a validation issue. Different stick :)