Use Validators and Load Generators to
Test Your Web Applications

HTML validators ensure that your web pages are correctly formatted.
Load generators stress-test your web servers to find performance problems.

Mike Crawford

Mike Crawford
Consulting Software Engineer

Copyright © 2001, 2012 Michael D. Crawford.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.



Did you know that there is a formal specification of what the HTML format means? And that there are different versions of the HTML format with different requirements?

If you test your HTML documents (whether they are static files or machine-generated by a web application) with a validator to ensure their conformance to one of the standards you can be sure they are viewable in any web browser - or rather, any web browser that is written to comply to the same standard.

While it is a good idea to check your pages by manually viewing them in all the different browsers that are available, this is tedious and does not catch all of the errors that a validator will - and such testing won't ensure your pages are viewable in a new browser that hasn't been written yet. This also won't give you meaningful feedback on what the problems really are; the best that you can hope for is that the page won't look right (or be displayed at all) if your markup is invalid.

Have you experienced slow response from a web application site? Maybe you thought they had a slow server machine or an inadequate connection to the Internet, or perhaps their user load was particularly high that day.

But maybe the service had plenty of resources - fast expensive servers and a fat pipe to an Internet backbone. Maybe you weren't sharing the service with many other users.

Maybe the server was just not capable of handling a high user load because its software was inefficiently written. Despite the huge investment and the hard work of our friends in the hardware business to obey Moore's Law by making faster machines year after year, it is trivial for a programmer to negate those gains by writing a few lines of bad code.

Have you had the unfortunate experience of putting your web application live on the Internet only to find that it could not handle a normal user load? This sometimes happens because the manual testing usually applied during development by programmers does not stress the server hard enough to reveal performance bottlenecks.

Using a load generator during your quality assurance phase and - more importantly - regularly by programmers to test their code during development will ensure that your application meets the challenge of real users. It just might save you a few hundred thousand dollars in server hardware and high-end hardware support contracts too.

Some Web Application Design Basics

Before we get started with quality assurance, let me put in a few words of advocacy: please take steps to ensure that your web pages are meaningful and usable to to the people who visit them. You'll save both yourself and your users a lot of annoyance, and you'll be more likely to achieve the objective you had in mind when you wrote your web site in the first place - conveying information, getting your point across, or making a profit.

I'm not talking about pretty rollover buttons here, folks.

You need to understand that many web sites are developed with investments totalling many millions of dollars, only to have the effect of driving away any user who might have the misfortune to stumble across them, with much resulting heartbreak and the loss of fortunes. So many web sites have failed lately that it has become a game to predict who's going to go bankrupt next (I won't give the url to the game...).

Don't let it be you.

Many others have written informatively on this how to write web sites that don't make your users feel like they're pounding nails with their fists. I encourage you to carefully consider their advice:

Homepage Usability cover

Homepage Usability
50 Websites Deconstructed

by Jakob Nielsen and Marie Tahir

[ Buy]

Jakob Nielson's Site (Usable Information Technology)

Useit arrives at good principles for web design through a remarkably obvious but sadly uncommon means - through actual user testing. For example, they use eye-tracking studies (see also the 1994 and 1997 reports) of users who are browsing web sites to determine what users tend to pay attention to on a page, and they gave a bunch of WAP-enabled cell phones to people in London to try out for a week to see how they liked using the Internet over a cell phone and published a study about their experiences.

Useit has pages of Top Ten Mistakes in Web Design to assist you in your design decisions - we'd all be better off if more sites considered these rules. - Your Source for Browser Compatibility Verification

Information and tools to help you ensure that your web pages will be viewable in any web browser. This is where I first found the W3 Consortium validator given below

Ask Tog

Bruce Tognazzini is one of the original designers of the Macintosh user interface and is a recognized authority on user interface design principles. He publishes articles on good user interface design both for web applications and for graphical user interface apps, and also critiques design problems he finds in published products.

The Cluetrain Manifesto cover

The Cluetrain Manifesto:
The End of Business as Usual

by Christopher Locke,
Rick Levine,
Doc Searls,
and David Weinberger

[Buy at Powell's]

The Cluetrain Manifesto

The Internet is a free-for-all, rather heady and spirited discussion. This can come as a rude awakening to many companies that are used to controlling their corporate communications through carefully defined channels.

Information is readily available to all on the Internet, nearly instantaneously and largely at negligible cost to the end user. This can work to your advantage if you learn to work with the new society, but it will work much to your disadvantage if you try to hold to the ways of the old.

This applies both to the public Internet and to private intranets, where employees have greater ability to discourse with each other and the public than ever before.

Next Page Previous Page Contents All Webmaster Tips Titles

How May We Be Of Service?

Please contact us today for a free assessment of your needs: - +1 (503) 688-8345

One Must Not Trifle With Wizards For It Makes Us Soggy And Hard To Light