Minimum versus useful
The hard minimum is 500 px on the longest side. eBay will accept that and the listing will publish, which is exactly why it is a trap — nothing tells you that you have published a listing without zoom.
eBay recommends 1600 px on the longest side so the zoom and enlarge tools activate. For anything where condition matters — and on eBay that is most things — this is the number to hit.
Borders and added text are not allowed
For most categories, eBay prohibits borders, added text and graphics on listing photos. This trips up sellers migrating from a platform where a branded frame or a "FREE SHIPPING" banner was fine.
If you have a workflow that stamps promotional text onto images, it needs a separate output for eBay. A plain watermark of your shop name is also risky here in a way it is not on Etsy or Instagram.
How many photos, and how large
eBay allows up to 24 photos per listing at no extra charge, and there is very little reason not to use them for a used item. Every angle you do not show is a question a buyer has to ask or a return you have to process.
Each photo can be up to 12 MB, which is generous — you will hit the useful-resolution ceiling long before the file-size one.
A plain background still helps
eBay does not mandate a white background the way Amazon does, but a plain, light backdrop on the primary photo makes a listing look considered and makes the item easier to see in a crowded search grid.
Common questions
What size should eBay photos be?
At least 1600 px on the longest side, which is what eBay recommends so the zoom and enlarge tools activate. The hard minimum is 500 px, but listings at that size publish without zoom.
Can I add text or a border to eBay photos?
For most categories, no. eBay prohibits borders, added text and graphics on listing photos. If your workflow stamps promotional text onto images, produce a separate clean set for eBay.
How many photos can I add to an eBay listing?
Up to 24 photos per listing at no additional charge. For used items it is worth using most of them — unshown angles become buyer questions or returns.
Does eBay require a white background?
No, unlike Amazon. A plain light background is still recommended for the primary photo because it makes the item clearer in search results.