Tools for testing sites
Whether you make websites or simply run a site someone else makes for you it's important to keep an eye on how well the site is working for visitors. These free tools will help.
A good website will be accessible and usable. An accessible site is one where visitors can access and use the content, whatever their circumstances.
An accessible site
They may be using older computers and older software; or perhaps software not many other people use. They may be blind and listen to a web page. They may not be using a mouse or keyboard and may control their computer by speaking to it or by blowing into a puffer switch.
An accessible website will allow all these visitors to get to the content you're providing. An accessible website will not force its users to have a particular size screen, to click on links with a mouse, to use a particular web browser.
A usable site
A usable website is one where it it easy for users to find the content and to get around from one page to another. Visitors will be able to use the website without being confused or lost, without getting frustrated.
Testing tools
If you are in charge of a website then you will need to be able to test that it works well for a variety of users. There are some free browser tools to help you do that.
Opera
The latest version of Opera includes a Toolbar for testing sites and for looking up specifications. This screenshot shows me choosing the high contrast white on black view of our website.

Firefox
Chris Pederick's Web Developer extension for Firefox, Flock, Mozilla and Seamonkey also gives you many tools for checking your web pages. The screenshot shows me checking for images missing the crucial alternate text.

Internet Explorer
The Web Accessibility Toolbar for Windows Internet Explorer has been developed to aid manual examination of web pages for a variety of aspects of accessibility. Features include:
- Integrated colour contrast analyser application.
- source highlighters and 3rd party DOM inspectors.
- Show blockquote and Q, Show internal links, Show Titles,Show Table headers and Navigation via link element.
- A dialog interface for screen reader and keyboard only users.
- Popup blocker detection for functions that open in new windows.
- Enable / disable hot keys for users who encounter key combination conflicts.

The screenshot shows me looking at our site with a small greyscale screen and zoomed text.