Juan José Nieva

Systems engineer and founder of NimboCDN. More than twenty years in ecommerce.

At NimboCDN he works on images: the size, the format, how they reach each visitor. He writes every piece of this blog the way he runs the service — no number without a measurement behind it, no comparison without the competitor's own page quoted and dated.

When something cannot be verified first hand, the piece says so instead of rounding it into a claim. Measured here means something specific.

Image formats are compared at matched perceptual quality, scored with SSIMULACRA2, and never at the same quality number: a JPEG and an AVIF set to the same value are not the same picture, so their file sizes are not comparable either. Weight is measured on real storefronts that the piece names and dates — the platform study behind this blog covered 41 of them across 14 ecommerce platforms.

The tools published here run inside the visitor's own browser and never upload an image to any server, which is also why their results can be reproduced without asking anyone for permission. The sources are first hand or they are not used.