HTML & CSS Validation Statistics for the 10 Biggest Websites In the World

Richard Cummings

10 years ago

Are you fretting that your website does not pass HTML and CSS Validation with flying colors? Never fear…take some solace in these HTML & CSS validation scores of the 10 most popular websites in the world.

As you will see in the chart below, none of the top 10 websites in the world passed both the HTML and the CSS test. Kudos go only to Wikipedia for passing the HTML validation and to the Chinese website Baidu, the only site that passed the CSS validation (to be fair though, the homepage tested hardly contains any information).

After enjoying the chart below, and perhaps feeling a little more validated about your site not passing, scroll down to the bottom and see who actually did pass the HTML validation test AND the CSS validation test.

HTML/CSS Validation Numbers for the 10 Largest Websites in the World

(all sites below were tested on the W3C website)

#	Site Name	HTML Validation Score	CSS Validation Score
1	Google	28 Errors, 4 warning(s)	Sorry! We found the following errors (10)
2	Facebook	36 Errors, 5 warning(s)	Sorry! We found the following errors (40)
3	YouTube	295 Errors, 2 warning(s)	Sorry! We found the following errors (746)
4	Yahoo!	272 Errors, 8 warning(s)	Sorry! We found the following errors (485)
5	Baidu	3 Errors, 4 warning(s)	Congratulations! No Error Found.
6	Amazon.com	997 Errors, 6 warning(s)	Sorry! We found the following errors (423)
7	Wikipedia	Passed, 21 warning(s)	Sorry! We found the following errors (4)
8	Taobao	Sorry! This document cannot be checked.	Sorry! We found the following errors (141)
9	Twitter	24 Errors, 4 warning(s)	Sorry! We found the following errors (79)
10	Tencent QQ	Sorry! This document cannot be checked.	Sorry! We found the following errors (89)

Who Passes the HTML & CSS Validation Tests?

Well, as I was running the sites above through the validator, I thought it almost fruitless to have this test since the best sites in the world don’t come close to passing. And, I also wondered: “Just who does pass the HTML and CSS validation tests?”

So, as I’m thinking of who to test that would probably pass, I had this thought: “Why not test the W3C Validator site itself?”

And wouldn’t you know it…they passed with flying colors (see images below).