ThumbHash

A very compact representation of an image placeholder. Store it inline with your data and show it while the real image is loading for a smoother loading experience. It's similar to BlurHash but with the following advantages:

Encodes more detail in the same space
Also encodes the aspect ratio
Gives more accurate colors
Supports images with alpha

Despite doing all of these additional things, the code for ThumbHash is still similar in complexity to the code for BlurHash. One potential drawback compared to BlurHash is that the parameters of the algorithm are not configurable (everything is automatically configured).