Store previews

Marketplace preview images are captured automatically: the platform renders your live demo URL in a headless browser and stores a desktop and a mobile screenshot. You don't ship screenshots in the package. Set the demo URL on your listing in the partner dashboard.

Preview	Captured as	Where it shows
Desktop	1440 px-wide viewport at retina resolution, cropped to a tall portrait of the top of the page	Listing card (when no thumbnail is set) and the theme detail page
Mobile	390 px phone viewport at retina resolution	Theme detail page

Captures run for approved themes that have a demo URL and refresh about once a day, so the listing images track your live demo site. If a capture fails, the listing keeps the last successful one.

Make the capture count

• The capture starts at the top of the page, so the home-page hero is what sells the theme. The desktop crop is portrait (taller than one screen), so the first couple of screens of content end up in the card.
• Whatever renders is what's stored: make the demo load fast and keep cookie banners, overlays, and placeholder content off it.
• Keep the demo site up. A dead demo URL means stale previews.

Optional thumbnail override

To control the listing-card image yourself, put a thumbnail.(webp|jpg|jpeg|png) at the theme root or in assets/:

my-theme/
  thumbnail.webp     # or assets/thumbnail.webp

When present, it replaces the auto-captured desktop preview on the listing card. It ships with the package, so a new thumbnail takes effect when the version carrying it is approved. Without one, the card falls back to the desktop preview.