Video thumbnails: the preview that plays when you hover a scene – Creator Support

When a visitor hovers over a scene card on your site, a short video plays inside the card. That preview is not your trailer. It comes from a separate file called a video thumbnail, set independently — this is the single most common mix-up creators run into.

Video thumbnail vs. trailer

Video thumbnail — a short, silent, looping clip that plays inside the scene card when someone hovers over it (or scrolls past it on mobile). No sound, no controls.
Trailer — the longer preview a visitor watches deliberately, on the scene page, by pressing play.

By default these are two separate things: replacing your trailer will not change the hover preview, and vice versa. If the wrong clip is playing on hover, the video thumbnail is what you need to change.

You can now choose to use your trailer as the hover preview instead — see Using your trailer as the hover preview.

Where to find them

Go to Content → Scenes and open the scene's thumbnail options.
Open the Custom tab in the thumbnail window.
You'll see two groups: Video Thumbnails and Extra Thumbnails.

The three video thumbnail slots

Video thumbnails are fixed slots, each used in a different place:

Desktop Preview — plays when a desktop visitor hovers a scene card.
Mobile Slider — used in the mobile slider.
Mobile Preview — the preview shown to mobile visitors.

Each slot holds one clip. Uploading to a slot replaces whatever was there.

File requirements

Format: MP4 only. Other video formats are rejected — convert first.
Size: up to 50MB. Aim well under that; these load on every card in a grid, so a heavy file slows your whole page.
Keep them short (a few seconds) — they loop, and they're silent.

Regenerating them

Video thumbnails are generated automatically from your source video during encoding. If they came out wrong — sideways after a portrait upload, or missing entirely — click Regenerate. This re-encodes from the source video and rebuilds the set. It's the first thing to try before uploading your own.

Extra thumbnails

In the same Custom tab, Extra Thumbnails are additional still images your site layouts use (sliders, hover states, featured placements). You can drag them to reorder, then click Update to save the new order — or Cancel changes to discard. You can also delete individual thumbnails.

Troubleshooting the hover preview

"The hover video is the wrong clip" — change the Desktop Preview video thumbnail. Changing the trailer won't affect it.
"It's sideways" — usually a portrait source video. Click Regenerate.
"There's no hover video at all" — the scene has no video thumbnails. Regenerate, or upload MP4s to the slots.
"It's different on my phone" — mobile uses the Mobile Preview / Mobile Slider slots, not Desktop Preview. Set those too.
After any change, clear your cache and hard-refresh — see Content not showing up on your site? Clear the cache.

For the main card image, custom uploads, and trailers, see Thumbnails and trailers.

Note: video thumbnails are sometimes referred to as "special thumbnails" in older documentation and in YPP CMS. They're the same thing.