Tools for checking accessibility

The page features free accessibility tools and assistive programs.

There are plenty of good free browser features and installable add-ons available for accessibility checking purposes. Paid versions of checking tools provide more features that can be used. All of the tools and assistive programs listed on this page are provided free of charge, but some of them require registration.

The accessibility of websites can be assessed by carrying out a programmatic check by means of either an external service or a checking tool built into or installed onto a browser. However, programmatic checking tools are unable to correctly judge all aspects, so any ambiguous notifications must be verified with a manual check. One prerequisite for accessibility checking carried out by content producers is that they have access to appropriate applications.

Other useful aids

Functional impairment simulation

It is often useful to have a mental image of how a functional impairment affects the way the person perceives the contents of a page. There are several different simulators for this purpose that can be used to examine how visual impairments affect the perception of contents.

One example is the NoCoffee add-on that can be used to illustrate many problems caused by impaired vision.

Checking the use and meaning of images

Images often play a significant role in the contents of pages. A good and easy way to check the alt texts of images and the functionality of the page without images is to use the ON/OFF add-on. This add-on makes it possible to hide all images with the press of a button, whereby the browser will display the page without images, replacing them with their alt texts.

Websites to help with checking

There are online services available for checking the accessibility of websites. Some of the checking sites offer auditing for a fee, while others will check the page similarly to the browser tools mentioned above. Checking tools installed into a browser are the easiest to use and always available to publishers.

Examples of websites for accessibility checking include the following:

The check carried out by the Siteimprove page only lists any issues detected but does not indicate where the issues are located, nor does it provide any detailed information about the technology of the page. Such a test result is not useful from an end user’s perspective. Instead, the Siteimprove browser extension works well and is recommendable.

There are also so-called one-aspect pages for checking the accessibility of a website, such as colour contrast checking pages. Examples of such pages include: