The storage Event

Storage Events

The storage event fires in other tabs (not the current one) when localStorage changes. Use it to sync state across multiple tabs.

Example

// Listen for changes from other tabs
window.addEventListener("storage", (event) => {
  console.log(event.key);      // Changed key
  console.log(event.oldValue); // Previous value
  console.log(event.newValue); // New value
  console.log(event.url);      // URL of the tab that changed it

  if (event.key === "theme") {
    document.body.dataset.theme = event.newValue;
  }
});

// Trigger by changing localStorage in another tab
localStorage.setItem("theme", "dark");

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Pro Tip

The storage event fires in OTHER tabs — the tab making the change does not receive the event.

Related Resources

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