2000x2000 is the number marketplaces reach for when they want a buyer to zoom into a product. Walmart specifies 2000x2000 pixels at 300 ppi for zoom capability, with 500x500 at 72 ppi as the floor for items that will not zoom — and it unpublishes SKUs whose primary image drops below that floor. Wayfair asks for at least 1000x1000 to be featured and says 2000x2000 will highlight every detail. Both are telling you the same thing: the marketplace will resample your image to whatever surface the shopper is on, and a square 2000px master is big enough to survive that without turning into mush. Two traps. First, do not upscale — Walmart explicitly says not to enlarge a low-resolution image to hit these requirements, because you gain pixels and no detail. Second, resize before compressing, because dropping a 6000px original to 2000px removes most of the file size before the quality slider does anything. Skwish does both in the browser, in that order, with a live readout per file and a batch queue. Originals stay on your disk.