Should users be able to change font size?
Im developing a site that will be used to some extend by visually impaired. My client has requested buttons that the user can use to change font size, like this:
My question is if you think its really necessary to provide this types of buttons, considering the possibility to change font size in the browser (ctrl++)? Should I convince him it is not necessary?
WCAG 2.0, guideline 1.4.4 "Resize text"", Level AA:
Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.
One way to meet this guideline is using such a widget as in your screenshot (if it zooms up to 200%): G178: Providing controls on the Web page that allow users to incrementally change the size of all text on the page up to 200 percent:
The purpose of this technique is to provide a mechanism on the Web page to incrementally increase the size of text. Many people with low vision do not use magnifying software, and they may not be familiar with browsers text size adjustments. This may be particularly true of older people who are learning about computers later in life and who may be experiencing age related vision loss. It may also be true of some people with cognitive disabilities who also require increased font size.
However, there are other ways how to meet this guideline. E.g. if your visitors use user-agents that provide this functionality, you don’t have to offer the functionality yourself: G142: Using a technology that has commonly-available user agents that support zoom
See: