CSS Grid and WebVTT enable dynamic TV-style squeezeback layouts on web video

The broadcast squeezeback, which traditionally required a pre-rendered motion graphic created in After Effects, can now be built directly in the browser with CSS Grid. By placing the video element in the centre cell of a 3×3 grid and animating the track sizes, the surrounding cells open or close to reveal overlay panels. This eliminates the need to bake the animation into the video file and lets the layout change at playback time.

WebVTT files supply the timing information for those layout changes. Each cue carries an identifier that becomes a layout key, and the cue text holds the desired layout name (e.g., right-rail, lower-third, squeeze). When the video player loads the track as a metadata track, the browser fires a cuechange event whenever a new cue becomes active. The application reads the cue’s id and text to set the appropriate grid-template values on the container.

Using Video.js v10, the developer selects the text track with selectTextTrack and subscribes to its cuechange event. The track is set to mode hidden so it does not display captions, but its activeCues are still accessible. Upon receiving a cue, the code updates the container’s dataset layout attribute, which triggers the CSS transition defined for grid-template-columns and grid-template-rows. No requestAnimationFrame loop or manual transform on the video wrapper is required.

Adopting this pattern requires familiarity with CSS Grid transitions and WebVTT syntax, as well as a player that exposes text-track cues (Video.js v10 works out of the box). The technique relies on browser support for CSS grid animatable properties and WebVTT metadata tracks; older browsers or environments without those features will not see the squeezeback effect. Additionally, the math for gaps and track fractions must be done manually because a grid container cannot query its own size, limiting fully automatic responsive adjustments.