Broadcast Channel API Demo

The Broadcast Channel API allows simple communication between browsing contexts (windows, tabs, iframes) of the same origin. It creates a named channel where any context can post messages that are received by all other contexts listening to the same channel. It's ideal for real‑time synchronization across tabs, such as updating UI when a user logs out in another tab.

The API is supported in all modern browsers: Chrome (54+), Firefox (38+), Edge (79+), Safari (15.4+), and Opera (41+). Note that Internet Explorer does not support it. Our demo automatically checks your browser's support.

localStorage fires storage events only when changes occur in a different tab and the event carries key, oldValue, and newValue. The Broadcast Channel API provides a dedicated messaging interface without polluting storage, allows structured cloning of complex data (objects, arrays, typed arrays), and works across same‑origin iframes as well.

Any value that can be cloned using the structured clone algorithm is allowed. This includes primitive types, objects, arrays, Maps, Sets, Dates, ArrayBuffers, and even Blobs. Functions and DOM nodes cannot be sent.

Yes, you can create multiple BroadcastChannel instances for different channel names. To avoid memory leaks, always call channel.close() when the channel is no longer needed (e.g., on page unload). In our demo, the channel is automatically closed when the connection is changed or when the page is closed.

Common scenarios include: synchronizing login/logout state across tabs, broadcasting live content updates (e.g., stock tickers), coordinating multi‑tab workflows (like an admin panel), and implementing inter‑iframe communication in same‑origin embeds.