All major browsers have built-in functionality for text scaling, either through changing the default settings or by using specific keyboard commands (Ctrl or Cmd and the plus and minus keys). Using these functions will only adjust the text, preserving page layout.
Using responsive design can help maintain a page’s readability when text is resized. This includes using percentages instead of pixels for sizing and placement of page elements and not limiting the height of containers that include text.
In most cases, visual content (images, illustations, graphs, etc.) will scale along with the page as users zoom in and out. Using quality visual content will help maintain clarity as the image size changes.
It is generally not recommended to use images of text or images that include text, as these do not scale well. If text on an image isn’t necessary, remove it and provide the text in a caption or accurately describe the visual information in the page content. The latter is especially important when using tables, charts, graphs and other visualized data.