Tampermonkey Script Activation Guide for Chrome, Opera, and Edge

Due to new security policies (Manifest V3) in Chromium-based browsers (Chrome, Opera, Edge), manual approval is required for userscripts to run. If your scripts work in Firefox but remain inactive in these browsers, follow the steps below.

🛠️ Solution Steps

1. "Allow User Scripts" Setting (New)

According to the official Tampermonkey (v5.3+) announcement, the browser must explicitly grant the extension permission to execute code:

Right-click the Tampermonkey icon in your browser.
Select "Manage Extension".
Scroll down to find the "Allow User Scripts" toggle and switch it ON.
Note: This setting is mandatory for Chrome/Edge 138+ and recent Opera versions.

2. Enable Developer Mode

Google requires this mode to be active for extensions to utilize the userScripts API:

Enter the appropriate address for your browser in the address bar:
- Chrome: chrome://extensions
- Opera: opera://extensions
- Edge: edge://extensions
Switch the "Developer Mode" toggle in the top right corner to ON.
It is recommended to restart your browser for the changes to take full effect.

3. Extension Permissions and Access Control

Go to the "Details" section of Tampermonkey in the extension management page.
Enable the "Allow access to file URLs" option.
Ensure that the Site Access setting is set to "On all sites".

4. Additional Settings for Opera Users

Opera's built-in features may block scripts:

Ad Blocker: Click the blue shield icon in the address bar and disable the blocker for the specific site.
Battery Saver: Go to browser settings (Alt + P) and turn off "Battery Saver"; this mode may suspend background scripts.

🔍 Technical Explanation & Source

As stated in the official Tampermonkey FAQ (Q209), Google has implemented a "two-step authorization" process to prevent code from running without explicit user consent. Simply installing the extension is no longer enough; the user must either enable Developer Mode or manually trigger the "Allow User Scripts" toggle in the extension settings.

Official Source: Tampermonkey FAQ - Q209: Permission to execute userscripts