20 Days Of Web Testing > Is the HTML valid?


HTML is the main underlying markup language of websites and other web delivered content.

Poorly constructed HTML can lead to bugs, rendering issues, browser compatibility issues and poor accessibility compliance, so it’s a good area to look for when web testing.

Adherence to standards can also help to ensure your site is future proof too.

There are many sites that don’t adhere to the typical HTML standards including some high profile sites. Reasons for non-compliance to standards are often cited as speed and cross browser support (which is ironic since HTML standards are aimed at ensuring cross browser conformance) but that’s something I’m not digging deeper in to here.

I’m struggling to find a WordPress template that adheres to accessibility and html standards also – I’m working on it 🙂


Suffice to say that it would be prudent to run a basic HTML compliance check using one of the many tools available.

It will give you a starting point for discussion anyway, whether your business decide to fix the issues or not.



Tools like HTML Validator Firefox extension will help you validate as you test.

There are also several validators online that give you quick feedback on the validity of the HTML under test.

These validators will give you information on what part of the HTML is failing validation and also pointers as to what can done about it.


Useful Hint

How about encouraging the programmers on your team to install development IDE compliance checkers if they are available. This is the ultimate early warning against HTML validation errors.


Useful Links

Good post on why you should validate – http://www.stevefenton.co.uk/Content/Blog/Date/201108/Blog/Do-I-Need-To-Validate-My-HTML

The W3C validator – http://validator.w3.org/

HTML Validator – https://addons.mozilla.org/en-US/firefox/addon/html-validator/

FireWeasel – https://addons.mozilla.org/en-US/firefox/addon/fireweasel/


If you want to talk Testing – catch me later this year at EuroSTAR conference.