Tools of the Trade: HTML Validator

Posted by on May 21, 2007 at 01:14 PM

Hello, and welcome back to a second installment of our Tools of the Trade series. This time, I'd like to introduce you to one of the older tools in our toolbelt, something that I've been using for several years now.

Like my last tool of the trade, HTML Validator is another Firefox extension, this time written by Marc Gueury, and once installed it quietly sits in your statusbar. Let me elucidate:

What does this HTML Validator do? Glad you asked! HTML Validator (let's just call it HV for a bit, all those letters are getting a bit repetitive) embeds an HTML validity test into your running Firefox process.

Using the plugin is very straight forward, just browse the internet, or your corporate home page as usual, but keep checking your statusbar. If the new icon is a happy green check mark, everything's golden, keep it up. When the indicator turns into the universal yellow warning sign then there's something minor amiss with the page markup.

Common warning causes are unescaped HTML entities, such as the infamous ampersand (&), or improperly closed and nested tags. These problems generally won't prevent the page from rendering properly, but can cause unforeseen maintenance problems later on. Finally, should the indicator turn red, HV found some serious validation errors in the page. A validation error can cause certain browsers (or even spiders!!!) to fail to recognize all the content of your page.

When HV detects any problems, you can point your mouse at the icon to get a brief description of how many outstanding issues it detected. To learn more information about which concerns HV discovered in your site, bring up the view source on a page with errors or warnings and you'll notice that the source view has an extra section at the bottom of it. In the left column is a listing of all the warnings, errors, and (if configured) accessibility warnings in the current page, along with a message indicating what was wrong on the shown line. In the right pane is a description, sometimes more helpful than others, that attempts to explain the currently selected item on the left.

Why does HTML validation matter to you? Well, I hinted at it above, but the biggest concern is that a poorly structured or invalid HTML page could be more difficult for the all important search engines to index, or in the worst case, could cause the site to fall into a dark and dangerous world where the spiders fear to tread.

But in all fairness, a far more satisfying reason is probably all the mad street cred your organization will get from fellow HV users browsing the interwebs.

Read Orien's previous Tools of the Trade blog post.

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