Learn to use an HTML validator to create perfect HTML that displays as you expect it to.
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.
Validate Your HTML
Use this form to validate your HTML against the W3C specification.
Validate Your XHTML
Use this form to validate your XHTML against the W3C specification.
Using an HTML Validator
It's all very well to know that you should use a validator, but sometimes they can be very confusing to use. Learn how to use Dr. Watson, one of my favorite validators. From your HTML/XML Guide at About, Jennifer.
Why Validate Your HTML?
It's important to validate your HTML, and this article by Jennifer Kyrnin, your HTML/XML Guide explains why.
CSE 3310 HTML Validator
This HTML validator is especially nice for people who do most of their pages on a PC and then upload them. [win95, winnt]
Dr. Watson checks browser extensions, spelling, and basic HTML. I especially like the style checking. It has many options, and is very easy to use.
HTML Power Tools
This software will analyze your HTML, do spell checking, link checking, manage your meta tags, and much more. [win95, winnt, win31]
NetMechanic emails the results of the tests to you. It tests the server, HTML, and links.
The W3C Markup Validation Service
This is the validator I use. It validates HTML and XHTML against the standards. I especially like that I can upload a file to be validated, so I don't have to post something until it's completely correct.
WDG HTML Validator
The results can be a little confusing, but this validator does a good job of showing you what you're doing wrong.
HTML Validator Errors Explained
HTML validators give errors that can be confusing. This article takes a look at the errors an HTML validator got on a live page and what they mean.