A highly rated tool specifically for multi-monitor setups. It allows you to control the brightness of all connected displays using DDC/CI.
If you find that your Windows 10 brightness slider is missing or you need a more powerful way to manage multiple monitors, you have two primary options: restoring the built-in Windows features or downloading a specialized third-party utility. 1. Best Third-Party Utilities to Download download windows 10 brightness slider
When the native Windows slider isn't enough—especially for external monitors—these downloads are the most popular solutions: A highly rated tool specifically for multi-monitor setups