Help.

Not for your own videos. Saving wallpapers from the catalogue, and using Seasill or Seasill Pro, needs a Seasill account: an email address and a password. You can make one on seasill.com; the Free plan costs nothing.

On the Mac the system plays the wallpaper, so it has to be chosen once: open System Settings › Wallpaper and pick any Seasill wallpaper. From then on Seasill switches wallpapers itself.

If Seasill says it “isn’t your wallpaper yet” for one display, choose it for that display too.

The wallpaper library lives inside the system’s own wallpaper container, and macOS asks once before an app may use it. Seasill reads and writes only its own library there.

SmartScreen can warn about new software until enough people have installed it. Download setup only from seasill.com; then choose More info, and Run anyway.

Seasill and Seasill Pro each begin with a 7-day free trial. A card starts it, and nothing is charged if you cancel before it ends; otherwise it becomes a yearly plan. Sales are not open yet, so the first trials start with the first release.

On Free, catalogue wallpapers play at up to 1080p with a small Seasill mark in a corner. Your own videos never carry it. Seasill and Seasill Pro remove the mark and play every wallpaper at its full resolution.

On Free, one display plays live and the others hold a still of their wallpaper. Setting a wallpaper on another display makes that one the live display. Seasill and Seasill Pro play every display.

Free keeps five catalogue wallpapers in your library at a time. Remove one to make room, or move to Seasill or Seasill Pro, which keep as many as you like.

Sign out in Seasill on the old computer, or remove it from your account on seasill.com; then sign in on the new one. Seasill covers one computer and Seasill Pro three, in any mix of Mac and Windows.

Yes. Seasill checks your plan when it can, and keeps it for up to two weeks without a connection. Browsing the catalogue needs one.

Seasill pauses when windows cover the desktop and plays a lighter version on battery. The line at the bottom of the window, and in the menu-bar or tray popover, always says which, in a sentence.

Pause in that same place is yours: if it says “Paused by you”, press Resume.

macOS can only play some kinds of video as a wallpaper, so Seasill converts the others when they arrive. That needs FFmpeg. Without it Seasill refuses the file and says how to get it.

Not on the Mac: macOS gives the wallpaper no way to play from the network, so a link is always downloaded. A long YouTube loop is cut to one loop first, so it is small.

Over a remote session Windows draws the wallpaper as a still picture. At the machine itself it plays.

Settings › Lock screen. Showing it live needs a small service, which setup installs; it stays off until you turn it on.

No. Quitting the app leaves the wallpaper playing. Pause stops it; choosing another wallpaper in your system’s settings replaces it.

Once sales open, from your account on seasill.com; until then, write to support@seasill.com. Your plan runs to the end of the period you have paid for, then your computers move to Free, and nothing is deleted.

From your account page on seasill.com, with your password. A paid plan that is still running has to be cancelled first. Deleting the account removes it, its sign-ins and its computers; see Privacy for what is kept, and for how long.

In Seasill’s Settings, under Advanced, “Restore my original wallpaper” puts back the wallpaper you had before Seasill.

Choose any other wallpaper in System Settings › Wallpaper. Seasill never replaced yours; it only drives the entry you chose.