Resizing and compressing are two separate problems and audiobook covers need both. Resizing is a geometry fix: the cover has to be square at 2400x2400 because that is what ACX, Audible, Findaway, and Spotify Audiobooks all accept. Compressing is a weight fix: dropping the pixel dimensions of a 4800px source to 2400px already removes roughly three-quarters of the pixels, and a quality pass on top takes the file down further without a visible difference at storefront size.\n\nDo the geometry first, at the highest quality available, and let the resample be a clean one. Resizing a compressed file re-encodes it and bakes in the old artifacts. Skwish applies both steps in the browser, so the artwork stays on your machine throughout, and the batch flow lets you run an entire catalogue through the same setting.