1. Accessibility & Legislation
  2. Common Issues
  3. Testing & Tools
  4. Analysing Your Site

2.02.05 JavaScript usage: Pop-Up windows

2.5 Pop-up Windows

Pop-up windows provide a unique accessibility problem. First of all, most usability experts would argue against the use of pop-up windows except in the most extreme of cases.

If you must use pop-up windows, know that they introduce several very unique accessibility issues:

  1. For a visual user, it may be difficult to notice and navigate to the new window
  2. For someone who is using assistive technologies, the new window may be annoying and confusing because the default behaviour for the link has been modified.
  3. JavaScript implementation may make the new window difficult or impossible to resize or scale for someone using a screen enlarger
  4. For someone who is blind, there is typically no indication that they are presently navigating in a new window. When the screen reader user attempts to return to the previous page by selecting the back button, it may be confusing to find that this does not work.

Pop-up example

Select this link to open a new window

<a href="popup.htm" onclick="window.open(this.href); return false;">Select this...

Note: If you are using software to block pop-up windows, you may need disable the software or select the link in a way that bypasses the pop-up blocker (typically Control + click or Control + Enter with the link selected).

In the example code above, the link will continue to work normally if JavaScript is disabled.

When using JavaScript to open new windows, you can modify the size and position of the new window. You can also add or remove functionality of the window, such as the ability to resize, display scroll bars, show tool bars, etc. Be very careful when changing the default behaviour of the browser window. If a user has low vision and must enlarge the content, a small window that cannot be enlarged and does not display scroll bars would be very inaccessible. Someone with a motor disability may rely upon large tool bars to accurately control the Web browser, so removing or modifying them may introduce difficulties for this user.

As you can see, there are many difficulties in both usability and accessibility that arise through the use of pop-up windows. Care must be taken in making the decision to use them. If they are used, thorough user testing of your implementation is vital to ensure accessibility. Always alert the user to the fact that a pop-up window will be opened.


Accessible pop-up windows

If you absolutely positively must use a pop-up window then please consider using the method outlined by Ian Lloyd at accessify.com.

There is even a pop-up window generator available.


Question 5.

Which of the following are accessibility problems that may arise when using pop-up windows? (Choose all that apply)