IconVault's Media Session Playground drives the real `navigator.mediaSession` API: build metadata (title, artist, album, artwork), flip the playback state between playing and paused, and register action handlers for play, pause, next track and previous track that respond to your keyboard's actual media keys, headset buttons and OS media controls. It is free and runs fully in your browser.

You will learn why every audio and video app should set media metadata: it powers the lock-screen player, notification controls and picture-in-picture overlays on phones and desktops. The lab shows which artwork sizes each platform prefers, how `setPositionState()` keeps scrubbers in sync, and the graceful pattern for handlers the browser does not support: check first, register only what exists.