The state of HTML validation

There’s been a lot of talk about HTML5 recently and, in some geek cir­cles, there have been snick­ers when com­pa­nies have done a poor job of imple­ment­ing it. But what is the true state of html5. To find out, I decided to check whether the top sites on the inter­net had imple­mented it and how suc­cess­ful they were in doing so.

Method­ol­ogy

One of the first thing in this effort was to get a decent list of sites. Unfor­tu­nately, it seems that it has become increas­ingly dif­fi­cult to get a sense of which sites are the most pop­u­lar when it comes to num­ber of vis­its. I even­tu­ally set­tled down on Alexa’s Top Sites list because it fea­tured most of the sites peo­ple think of when con­sid­er­ing what large sites are and includes a few non-US sites.

I then used the W3C Val­ida­tor against each of the top 25 sites. This allowed me to get 3 dif­fer­ent pieces of information:

• Doc­type: This is what the site declares as its HTML code ver­sion. In other words, how the site iden­ti­fies what ver­sion of HTML it supports.
• Encod­ing: This is the lan­guage the site uses, which gives us a bet­ter under­stand­ing as to whether they are tar­get­ing a par­tic­u­lar lan­guage or try­ing to offer a global site.
• Val­i­da­tion: This is how the site val­i­dated when tested for errors relat­ing to the HTML ver­sion it pur­ported to be offer­ing. It gives us an idea as to how com­pli­ant with the stan­dards the site truly is.

Sur­pris­ingly, a num­ber of pop­u­lar Web 2.0 sites were not in Alexa’s Top 25 so I cre­ated a sep­a­rate list for them.

Top 25

Look­ing at the top 25, here are the results:

Look­ing at the data, the first thing that is inter­est­ing is how many sites have made the switch to HTML 5. Of the top 25 sites, 14 have made the switch to HTML 5. This means than in the last year, 56 per­cent of the largest sites on the inter­net have com­pletely mod­i­fied their code base to com­ply with a new stan­dard. 6 sites are still left on the old HTML stan­dard and 5 are stick­ing to the some­what more recent XHTML standard.

How­ever, it is also inter­est­ing to note that none of the sites which have made the tran­si­tion com­ply with proper HTML stan­dards. In fact, of the top 25 sites in the Alexa list, only MSN was found to pro­vide com­pletely valid code. Maybe Microsoft could point those peo­ple towards their other prop­er­ties. Ama­zon was the worst offender, with 516 errors in their code, show­ing that dis­re­gard for stan­dard com­pli­ance does not seem to have an impact on eco­nomic per­for­mance. However, Ebay and Yahoo came closely behind with hun­dreds of errors in their code, maybe high­light­ing Ama­zon as an exception.

Another inter­est­ing phe­nom­e­non is that most of the large sites have adopted UTF 8, the encod­ing type that sup­port most lan­guages, as their default lan­guage. Once again, over half (56%) of the sites have switched with Ama­zon and Google being among the rare excep­tions. An inter­est­ing aside here is that the W3C val­ida­tor may have issues when it comes to val­i­dat­ing chi­nese sites as it was not able to fin­ish the job.

Web 2.0 Companies

Look­ing at Web 2.0 com­pa­nies, the data was surprising:

I cap­tured the data for com­pa­nies other than those in the top 25 and a few inter­est­ing trends seem to pop up. The first thing that came as a sur­prise is that there seems to be that a lower num­ber of sites have made the tran­si­tion to HTML 5, with only 5 sites out of 11 (or 45 per­cent) hav­ing com­pleted the tran­si­tion. There seems to still be a strong pref­er­ence for XHTML as the way to encode pages.

Also of note is that all sides have plans for glob­al­iza­tion, encod­ing their page in the UT-8 for­mat that can sup­port both west­ern and non-western alphabets.

How­ever, none of the sites suc­cess­fully val­i­date in any of their pre­ferred stan­dard. It looks like there is still much room for improve­ment in the world of HTML validation.