A fireworks overlay is a short clip of fireworks on a plain background that you lay over your own footage, so the bursts appear in your shot. Editors use one for New Year's, the Fourth of July, a birthday, a launch, a milestone or any moment that calls for a celebration.
This maker draws the fireworks for you. Shells rise on a trail and burst into peonies (round balls of stars), rings (a tilted circle with a small core) and willows (long trails that droop and hang), then sparkle and burn out. Each burst gets its own place, size, color and moment, and the whole show can run as a seamless loop.
It opens on pure black, where each burst glows as light. In your editor, set the clip's blend mode to Screen: the black disappears and only the light of the fireworks stays over your video. For a person on camera, Upper half opens the bursts above them; for a night sky or a title card, let them use the whole frame.