Placeholder Images

The primary goal of unlazy is to provide a smooth transition from a placeholder image to the actual image. A common approach is to use a blurry version of the actual image as a placeholder.

Inlining a blurry placeholder is not always practical, e.g. when loading images from a CDN. In this case, you can use hash-based placeholders like BlurHash or ThumbHash. Both are compact string representations of placeholder images.

unlazy supports the following hash-based formats:

• BlurHash – Compact string representation with good blur quality
• ThumbHash – More compact with better quality and automatic aspect ratio encoding

Learn more about hash-based placeholders.