Visually rendered text, including text-based controls should be able to be scaled without using special assistive technology like a screen magnifier. Users may benefit from scaling all content on the Web page, but text is most critical.
1.4.4 Resize text: Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.
How to fix:
- Specify font sizes in relative units like ems, percentages, or use named font sizes.
- Specify the sizes of text containers in relative units like ems, so that they scale along with the contained text.
- Consider using a "liquid" page layout, that expands, contracts and reflows as the browser viewport is expanded or contracted
- Where possible, use actual text rather than images of text. Even if a browser is capable of scaling the image text, it's apt to look blurry and or pixellated.