Text layout and natural metrics
For text layout in IE9 Standards mode (and later), Windows Internet Explorer 9 uses natural metrics instead of the Windows Graphics Device Interface (GDI) metrics that other Windows browsers use.GDI metrics align text to pixel boundaries, but natural metrics use inter-pixel spacing to create more accurately rendered and readable text.
Other document modes for Windows Internet Explorer continue to use GDI metrics.
Page layouts that are written for earlier document modes might display incorrectly in Internet Explorer 9. The most common error is unexpected text wrapping, which can cover elements that are below the wrapped text. This error is most likely when a text box does not include extra horizontal space or when the size of the text box is connected to another element on the page, such as a graphic.
Do not assume that the size of a particular font renders identically across browsers or within the same browser because users can choose a larger font display (for example, 125%).
Use the following design guidelines to make sure that your webpages display text layout consistently:
- Set a text box's size to a specific number of pixels.
- Include extra space in your text boxes and avoid tight spaces.
- Use non-statically sized text boxes.
- Include extra space in bounding areas that depend on other page elements.
- Make sure your page can accommodate text wrapping if you permit users to change the page font size.
- Test your webpages in all common browsers. If you see a text wrapping issue, adjust the page to make sure the page appropriately renders the text.
- If you designed a webpage for a previous mode and you do not want to update it to use natural metrics, set the page to display in that mode even when users view it in Internet Explorer 9.
Avoid the following designs for text layout:
- Depend on font sizes to render the same way across browsers.
- Use static-sized text boxes.