🐞 How to Debug Offscreen Pages in Chrome Extension Manifest V3
Debugging offscreen pages in Chrome extensions using Manifest V3 can be tricky. Here are three effective methods to help you inspect and debug offscreen functionality.
1. 🔍 Use chrome://inspect/#other
Navigate to:
chrome://inspect/#other
This page lists offscreen pages created by extensions. You can directly access Chrome DevTools for your offscreen page to view console logs, inspect variables, and debug behavior.
2. 📤 Implement a Logging Relay System
If the offscreen page closes too quickly to inspect manually, use a helper function to relay logs to the background script.
In the offscreen page:
const log = async (...args) => chrome.runtime.sendMessage({
target: 'background',
type: 'log',
data: args,
});
In the background script:
chrome.runtime.onMessage.addListener((message) => {
if (message.target === 'background' && message.type === 'log') {
console.log(...message.data);
}
});
Usage:
log('clipboard initialized');
This method ensures you capture logs in the background console, even if the offscreen page terminates quickly.
3. 🔧 Inspect via Chrome Extensions Page
- Open
chrome://extensions - Find your extension and click Details
- Scroll to Inspect views
- Click on your offscreen page link
This opens a DevTools window tied specifically to your offscreen page for live debugging and inspection.
By using these methods, you can effectively debug your offscreen pages and overcome the challenges introduced by Manifest V3 restrictions.
If this helped you streamline Chrome extension development, share it with your fellow devs and follow the Mellowtel Team for more insights!