Selling a camper privately means posting the same photo set to more than one place, and each place has its own idea of an acceptable file. The dealer-backed platforms publish hard numbers — Boats Group caps photos at 15 MB each and 50 MB per listing, recommends 2160x1440 at 3:2. Bring a Trailer wants 1-4 MB per photo at 2000-3000 pixels and rejects anything over 10 MB. Free classifieds mostly publish nothing at all, which is worse: the listing just gets compressed server-side, badly, or the upload silently fails on a 9 MB interior shot. RV listings also have a specific composition problem. A motorhome is long, and the shots that sell it — the full side profile, the slide-out extended, the tow-behind setup — are wide, while the interior shots that prove condition are square-ish and detail-heavy. Shoot both, then crop each group to the ratio the platform displays, resize, and compress to a uniform weight so the gallery does not jump between file sizes. Skwish resizes and compresses in the browser with a per-file before/after readout and a batch queue, so 30 camper photos go through in two passes and come back as one ZIP. Nothing is uploaded.