Are 3 Image Sizes Enough for A Responsive Web Site?
The answer is: if you care about mobile performance and payload, then you need a better solution than only 3 image sizes. We evaluated over 53 million requests for images from 1.6 million distinct urls (see our MOVR report). On average, it takes only 8 requests to surpass the need for 3 image sizes. Resizing to the standard 3 versions helps reduce the payload to 63% of the original. But if you automatically detect the actual device, resize, and compress to an optimal size, then you can save 84% of the payload. For image-heavy sites with a large amount of mobile users, this performance improvement could have a big impact on user experience and e-commerce conversions, potentially generating millions of dollars.
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