Smart Refresh Rate

A small Windows utility that automatically switches your display's refresh rate: a power-saving mode when the charger is unplugged, and your preferred high-refresh mode when it's plugged back in.

How it works

• Polls the power state once every 5 seconds.
• On battery it applies each monitor's powersave-state mode; on AC power, its performance-state mode.
• Lives in the system tray. Idle CPU usage is effectively 0% — config.json is only re-read when the file changes.

Requirements

• Windows 10/11 (x64)
• A laptop with a battery (with no battery info available there is nothing to react to)
• No administrator privileges required — runs asInvoker; writes only to HKCU (autostart / uninstall registry) and uses ChangeDisplaySettingsExA to switch modes. No UAC prompt.

Quick start

1. Download SRR.exe from the latest release.
2. Run it once — it copies itself to %LOCALAPPDATA%\SRR, adds itself to autostart, creates a Start Menu shortcut and registers an uninstall entry. After that the downloaded file can be deleted.
3. On first launch it generates config.json from your monitor's current settings and starts working right away.

Configuration

%LOCALAPPDATA%\SRR\config.json contains one entry per monitor, keyed by the monitor's hardware ID:

{
    "MONITOR\\LGD0521\\4&abc&0&UID0": {
        "performance-state": { "width": 2560, "height": 1440, "refresh_rate": 165 },
        "powersave-state": { "width": 2560, "height": 1440, "refresh_rate": 60 }
    }
}

Edit it with any text editor — SRR picks up changes automatically within a few seconds. Monitors connected later are appended to the config automatically.

Command-line flags

SRR.exe --uninstall   # remove autostart, Start Menu shortcut, uninstall registry key and %LOCALAPPDATA%\SRR, restore default display modes
SRR.exe --version     # print the bundled version (from version.py) and exit
SRR.exe --config      # print the config file path (%LOCALAPPDATA%\SRR\config.json) and exit

Flags can also be combined with the installed copy: %LOCALAPPDATA%\SRR\SRR.exe --version.

Updates

• SRR checks for updates automatically on startup and every 24 hours (via https://api.github.com/repos/Mefgner/Smart-Refresh-Rate/releases/latest).
• The tray menu always shows Check for updates (click to check right away) and a status item beneath it: No updates yet when up to date, or Update available: vX.Y.Z when a newer release exists.
• Clicking Update available: vX.Y.Z opens the releases page in your browser. It does not auto-download or auto-install — download and replace the exe manually.

Logs

Runtime logs are written to %LOCALAPPDATA%\SRR\logs.txt (rotating file, 1 MB × 3 backups). Open it from the tray menu Open logs or directly in a text editor. The Open config folder tray item opens %LOCALAPPDATA%\SRR.

FAQ

How do I change settings? Edit %LOCALAPPDATA%\SRR\config.json (the tray menu has an Open config folder shortcut), then pick Reload — or just wait a few seconds.

How do I pause or close it? Right-click the tray icon: Pause/Resume temporarily disables switching, Exit quits. On exit your displays are restored to their default modes. The Run at startup checkbox toggles autostart.

Can I disable notifications? There is no in-app toggle — SRR always attempts to show notifications (tray balloons for config errors, update notices, etc.). To silence them, disable notifications for Smart Refresh Rate in Windows Settings → System → Notifications.

What if I launch it twice? SRR is single-instance (Windows named mutex via CreateMutexW). Launching a second instance shows a message box — "SRR is already running (check the system tray)" — and exits. No second icon is created.

How heavy is it on the CPU? SRR polls the power state once every 5 seconds and only reads config.json when its timestamp changes, so idle CPU usage is effectively 0%.

Antivirus false positives

SRR ships as a single-file executable built with PyInstaller. PyInstaller-packed binaries are a common target of heuristic antivirus detections, so some antivirus products may flag SRR.exe as suspicious even though there is no malware in it. If you see such a warning:

• build the executable yourself from source (see below) — this guarantees the binary matches the code in this repository;
• or add an exclusion for SRR.exe in your antivirus settings;
• or report the false positive to your antivirus vendor.

Uninstall

Use Settings → Apps → Installed apps → Smart Refresh Rate → Uninstall, or run %LOCALAPPDATA%\SRR\SRR.exe --uninstall. This stops the app, removes autostart, the Start Menu shortcut, the registry entry and the install folder, and restores default display modes.

Building from source

Requires Python 3.12. Run:

build.bat

The script creates a .venv, installs dependencies and produces dist\SRR.exe via PyInstaller.

License

MIT. Monitor icon by Maniprasanth — Flaticon.