Does this only work for Amazon listings?
No. It uses the same root batch optimizer, but starts from a square marketplace-oriented profile and page copy tuned for Amazon-style seller workflows.
Can I switch away from the square profile?
Yes. The square listing profile is only the default. The normal batch controls remain available once the tool is open.
Does the queue leave the browser?
No. Queue preparation, processing, and ZIP export all stay in the browser, with common metadata stripped on save.
Can I batch-produce compliant Amazon main images with this?
Partly. It gets you the 1600 x 1600 square, the white canvas and the JPG export, which is most of the spec. What it cannot do is remove a non-white background or zoom the product to Amazon's 85 percent fill rule, so those have to be right in the source images.
How many images can I run at once?
Up to 100 per queue, at up to 15 MB each. The results come back as a single zip you can unpack into a bulk upload.
Will a watermark get my listing suppressed?
On the main image, yes, it can. Amazon prohibits text, logos, watermarks and borders there. Keep the watermark off for main images, and be careful with the branded profile, which turns it on by default.
Why JPG rather than PNG?
Amazon accepts both, and JPG at 0.84 keeps the zip small enough to move. If your products are cutouts on white with hard edges, push the quality higher so JPEG ringing does not dirty the white right at the product edge.
Does it run on a server?
No. Every file is processed on a canvas in your browser and zipped locally, so nothing about an unreleased product listing leaves your machine.