Cross-Browser CSS Technique for SVG Sprites with PNG Fallback

We have crossed the 300DPI mark and came up with all kinds of wicked ways for responsive images. SVG is a strong contender, but its ubiquitous usage has been hindered by the lack of legacy browser support. So let's learn to deploy SVG with a safe PNG fallback.

SVG sprites are amazing: when created with the right tools and deployed correctly, they can be even smaller in file size than PNG8 while being infinitely scalable. It's a responsive Web-Designer's dream.

Sadly, required support for legacy browsers often forces us to resort to least common denominators. Yet we should refrain from using a 50kb JS library for feature detection or a 100kb JS library to add unsupported features. A simple CSS trick for progressive enhancement can safe the day.

A safe-to-deploy method including IE6+7

Legacy browsers such as IE6+7 cannot process RGBA color values in CSS. So when we combine a CSS background shorthand declaration containing RGBA with a URL to a SVG sprite, legacy browsers will not load it. They will resort to the prior rule of a PNG fallback version of the sprite.

The CSS code snippet

Cross-Browser CSS Technique for SVG Sprites with PNG Fallback