Recommendations

PageSpeed
YSlow

YSlow: Avoid AlphaImageLoader filter

Overview

IE's AlphaImageLoader blocks rendering and increases page load times.

How does your site score on this recommendation?

Details from Yahoo!

The IE-proprietary AlphaImageLoader filter attempts to fix a problem with semi-transparent true color PNG files in IE versions less than Version 7. However, this filter blocks rendering and freezes the browser while the image is being downloaded.

Additionally, it increases memory consumption. The problem is further multiplied because it is applied per element, not per image.

Summary

CSS
Medium
Moderate
98%

YSlow recommends:

The best approach is to avoid AlphaImageLoader completely and use gracefully degrading PNG8 instead, which are fine in IE. If you absolutely need AlphaImageLoader, use the underscore hack _filter as to not penalize your IE7+ users.

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