Recently validator.w3.org went down for about an hour

Do you check your sites for validity?

For example, google has never bothered with its mistakes, even in their first version there are 12 errors, they do not hide this and are probably close to the position: what's the difference, the main thing is that it works.

---

And then I wanted to know if there are errors on the sites I know

Check for validation of html code (on the site validator.w3.org) - 01/31/11:

• Google.com - 36 errors.
• Vkontakte.ru - 33 errors
• Habrahabr.ru - 37 errors
• Facebook.com - 12 mistakes
• Yandex.ru - 40 errors
• Rabota.kharkov.ua - 659 errors
• Youtube.com - 102 errors

---

The disadvantage of the fact that the site is invalid:

• Mobile phones only understand valid xhtml. (But for example, the same Google will recognize that you have opened the site from a mobile device, by the type of USER_AGENT device, and will provide you with a version for a mobile phone).
  
• Yandex bot very willingly eats valid code, and handles code with errors very poorly.
  
• Invalid code, which means errors in the code, are perceived differently by different browsers (code interpreters), and here you have cross-browser compatibility. It happens that you start tweaking something in IE so that it looks the same everywhere, but in fact it was necessary to correct errors in the code, and everything would probably fall into place.
  

There are other disadvantages, but these seem to me the most important.

---

So recently validator.w3.org went down for about an hour. And I needed it urgently, very urgently. After that, I decided to check the code on the local computer.
Therefore, I suggest you get this program:

CSE HTML Validator is a powerful utility for validating HTML code. Searches for errors in the text of a WEB page and lists them in a user-friendly format. There is a built-in HTML editor, tag converter, templates, hint wizards. Can work in batch mode. There is a version, both Lite and Pro (paid), that allows you to do the same on your local computer. The downside for some people may seem to be that the program is completely in English, and so is the necessary tool for the developer.