Poster Video

PosterVideoEngine is the Apple-homepage trick: ship only a lightweight poster <img>, and create the real <video> lazily as the poster nears the viewport. The video is overlaid on the poster, faded in once it can play, and then handed to a composed VideoEngine for autoplay and off-screen pausing. Until you scroll near it, there’s no <video> element, no decoder, no bytes.

Scroll the poster into view ↓

Poster onlyLoadingPaused

↑ scroll down to the poster

No <video> exists in the DOM until the poster nears the viewport.

↓ scroll up to the poster

How it works

The page ships with only the poster <img>. As it approaches the viewport, PosterVideoEngine creates a <video>, overlays it on the poster, and fades it in once it can play — then a composed VideoEngine autoplays it and pauses it off-screen. The poster takes its alt along.

Scroll the poster into view ↓

Poster only Loading Paused

↑ scroll down to the poster

No <video> exists in the DOM until the poster nears the viewport.

↓ scroll up to the poster

How it works

The page ships with only the poster <img>. As it approaches the viewport, PosterVideoEngine creates a <video>, overlays it on the poster, and fades it in once it can play — then a composed VideoEngine autoplays it and pauses it off-screen. The poster takes its alt along.

Scroll the poster into the panel — the <video> is created on approach, fades in, and starts playing.

Usage

Point the hook at a poster <img> inside a positioned wrapper. Pass the video sources; the engine does the rest.

import { useRef } from 'react';
import { usePosterVideo } from '@60fps/ui-react/poster-video-engine';

function Hero() {
	const ref = useRef<HTMLImageElement>(null);
	usePosterVideo(ref, { sources: '/hero.mp4', autoPlay: true, loop: true });

	return (
		<div className="relative">
			<img ref={ref} src="/hero-poster.jpg" alt="Product hero" className="w-full object-cover" />
		</div>
	);
}

<script setup lang="ts">
import { ref } from 'vue';
import { usePosterVideo } from '@60fps/ui-vue/poster-video-engine';

const poster = ref<HTMLImageElement | null>(null);
usePosterVideo(poster, { sources: '/hero.mp4', autoPlay: true, loop: true });
</script>

<template>
	<div class="relative">
		<img ref="poster" src="/hero-poster.jpg" alt="Product hero" class="w-full object-cover" />
	</div>
</template>

Responsive sources

A string is shorthand for a single src. Pass an array to emit <source> elements and let the browser choose by media / type (resolution per breakpoint, codec fallback):

usePosterVideo(ref, {
	sources: [
		{ src: '/hero-480.mp4', type: 'video/mp4', media: '(max-width: 600px)' },
		{ src: '/hero-1080.webm', type: 'video/webm' },
		{ src: '/hero-1080.mp4', type: 'video/mp4' }
	]
});

How it works

1. A first IntersectionObserver watches the poster with a generous preloadMargin (200px by default), so the clip is created and preloaded before it’s on screen.
2. On approach the engine creates the <video>, mirrors the poster’s object-fit / border-radius, and overlays it at opacity: 0 over the poster <img>, which stays behind as the placeholder (so the <video> needs no poster of its own).
3. As soon as the video has a renderable frame (loadeddata / canplay / playing, whichever fires first) it fades it in and emits ready — canplay alone is unreliable, so it isn’t trusted on its own.
4. A composed VideoEngine takes over playback — pause off-screen and the prefers-reduced-motion policy, plus autoplay when in view if you pass autoPlay. Reach it via engine.video.

Everything VideoEngine accepts is forwarded, so a lazy background clip is { sources, decorative: true } — silent, inline, hidden from assistive tech, autoplayed once in view, and reloaded when a media condition hands the win to another <source>. See decorative videos. Give the poster an empty alt in that case: the preset hides the video from assistive tech, so the accessible name it would inherit from the image goes unused — and a decorative pair should be silent to a screen reader anyway.

usePosterVideo(ref, options)

Extends every VideoEngine option — forwarded as-is to the composed engine. autoPlay is not defaulted here: the engine just lazily loads the video, so opt into playback yourself. Plus:

Engine events

The hook returns the engine — an emitter. Subscribe with engine.on(event, cb); reach the playback engine via engine.video: