While A1 Website Analyzer uses the W3C HTML and CSS validators when checking the HTML of all pages encountered during website scan, there exist alternatives for those who want it.

• CSE HTML Validator
• W3C HTML Validator
• W3C CSS Validator
• Validome Validators
• WDG HTML Validator

A common error (and the most common source of erroneous bug reports for the WDG HTML Validator) occurs when writing HTML tags within a SCRIPT element:

<script type="text/javascript">
<!--
  // This is an error!
  document.write("</P>");
// -->
</script>
As mentioned in the HTML 4 Recommendation's note about specifying non-HTML data in element content, end tags are recognized within SCRIPT elements, but other kinds of markup--such as start tags and comments--are not. This is an unintuitive quirk of SGML for elements defined to have CDATA content.

Authors should avoid using strings such as "</P>" in their embedded scripts. In JavaScript, authors may use a backslash to prevent the string from being parsed as markup:

<script type="text/javascript">
<!--
  document.write("<\/P>");
// -->
</script>
Note that in XHTML, authors must also take care when using start tags within a script element. For details, see the Script and Style elements section of the XHTML 1.0 Recommendation as well as the HTML compatibility guideline for embedded scripts.

Thanks you for adding your post to this thread Chris. Might help quite a few people. It is in fact true that sometimes HTML code inside Javascript can cause confusion for crawlers. e.g. if Javascript code has code like document.write("</script>") crawler might decide that's the closure of script code contents tag.


By the way, I see some people adding a custom signature to their posts. Please add signature to user profile settings instead. I have moved yours into that. Feel free to edit it if you wish

Best HTML Validators

To evaluate HTML validators I looked for the following features:

    * Validate against a defined DTD or schema
    * Validate groups of files in a batch
    * Validate HTML both online and offline
    * Display warnings as well as errors
    * Validate HTML, but also CSS, JS, Access, links, spelling, orphans, browsers, and speed
    * Price

    One Reason to Use Valid HTML
Writing valid HTML often seems like a nuisance, but one reason is if your site is moved into a database, valid HTML or really valid XHTML can become very important. Many CMS programs require valid XHTML because they are based on XML and installed in databases.

Common Validation Problems and How to Fix Them
HTML validators can be very intimidating to the novice Web developer. But if you learn a few simple steps you can turn the W3C validator and others like it into a valuable tool for solving problems with your Web pages.

Validate groups of files in a batch
Validate HTML both online and offline
Display warnings as well as errors

Writing valid HTML often seems like a nuisance, but one reason is if your site is moved into a database, valid HTML or really valid XHTML can become very important. Many CMS programs require valid XHTML because they are based on XML and installed in databases.

You would need this tool to hold your website viewable through the ever-changing versions of HTML. You can furthermore use this if you desire novel browsers to display your website. There are numerous different HTML validators accessible on the net. 

According to me evolution of web browsers, they nearly are able to read the standard HTML versions of web sites that were written by W3C. The problem is if you write with an HTML that is not up to par, there would be a tendency for newer version of browsers could not read all your website data as efficiently as it should. MY PERSONAL suggestion is that Making Your Site Viewable By All Browsers and  Html Validators Can Help You To Avoid Problems.

Quote from: Webhelpforums on April 29, 2010, 08:02:50 PM
While A1 Website Analyzer uses the W3C HTML and CSS validators when checking the HTML of all pages encountered during website scan, there exist alternatives for those who want it.

• CSE HTML Validator
• W3C HTML Validator
• W3C CSS Validator
• Validome Validators
• WDG HTML Validator

Thanks for providing these tools Now i can check all my website and correct the errors

Validate groups of files in a batch
Validate HTML both online and offline
Display warnings as well as errors

Unlike other HTML validation software, CSS HTML Validator features an unusually powerful custom syntax checking engine that is specifically designed to check HTML, XHTML, CSS, SEO, and more.