RefreshRate.app is a browser-based tool to measure how your display actually behaves in motion, not just what the Windows panel says.

It focuses on three things:

• How stable your frame pacing really is.
• How many distinct positions (“ghosts”) you can see in different time windows.
• How different FPS targets (30, 60, 120, 240, etc.) would look on your current panel.

• 🧵 Motion Tracks (ms lanes)
  Time-based tracks at 50 ms, 100 ms, 150 ms, 500 ms and 1000 ms. Each one shows a ball crossing the lane; the app estimates how many ghost positions you should see at your measured refresh rate.

• 📊 Live Metrics Panel

  • FPS (frames per second)
  • Frame duration (ms)
  • Refresh rate (Hz) from measured frame spacing
  • Pixels per frame / pixels per second
  • Aspect ratio
  • Screen resolution
  • System scale (%)
  • Screen orientation

• 👻 Ghost Counter per lane
  Shows how many distinct “snapshots” of the moving ball your display should be able to show in that lane, based on your current measured Hz.

• 🧪 Frame Rate Preview (canonical FPS lines)
  Animated rows for common FPS targets: 30, 60, 120, 165, 240, 360, 480, 600.
  Only FPS values at or below your maximum measured refresh rate this session are shown, plus a custom line for your exact panel Hz when it sits between presets.

• 📱 Responsive and PWA-ready
  Works on desktop and mobile, supports installation as a Progressive Web App and can run offline once cached.

• 🎛️ Simple controls
  Change:

  • Background lane color
  • Number of decimals for the metrics
  • Metrics update interval

1. Open the app
   Go to:
   https://refreshrate.app

2. Put the window where it matters

   • Move the browser to the monitor you actually care about.
   • Use the Fullscreen button for more consistent timing and motion.

3. Read the Motion Tracks (left panel)

   • Each lane has a label: 50 ms, 100 ms, 150 ms, 500 ms, 1000 ms.
   • The ball crosses the lane in exactly that time.
   • Under each lane you see “Expected ghosts”: this is
     refreshRate(Hz) × laneDuration(seconds) rounded.
   • On a good high-refresh panel, you should see many clean, distinct positions even on the short lanes (50 ms, 100 ms).
   • If everything looks like a smeared streak or you barely see steps on the short lanes, your effective motion clarity is worse than the number on the box suggests.

4. Watch the Live Metrics (right panel)

   • FPS and Frame Duration show how consistent the browser’s render loop is.
   • Refresh Rate (Hz) is computed from actual frame spacing, not from OS settings.
   • Pixels per Frame and Pixels per Second show how much work your panel is doing at that configuration.
   • Aspect ratio, resolution, scale and orientation are pulled from screen and devicePixelRatio.

5. Use the Frame Rate Preview (bottom-right)

   • Rows like 30 fps, 60 fps, 120 fps etc. are shown only if they are ≤ your max measured Hz this session.
   • A custom row like 143 fps (your panel) appears when your measured Hz sits between presets.
   • All rows cover the same distance, but the update cadence is tied to the FPS number, so you can visually compare:
     • How choppy 30 looks vs 60
     • How 60 compares to 120 / 144 / 165
     • Whether 240 on your panel actually looks meaningfully different from 165, etc.

The Motion Tracks use a simple idea:

• Your measured refresh rate is Hz.
• A lane duration is T milliseconds.
• Expected number of distinct positions is:

ghosts ≈ Hz × (T / 1000)