Hz & Ghosting Analyzer

Detect your monitor refresh rate and test for motion blur or ghosting with a canvas-based animation test.

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Free Client-Side Private
Refresh Rate Detector
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Detected Hz
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Average FPS
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Frame Time
Measures for 3 seconds. Keep this tab active.
Motion Blur & Ghosting Test
Speed
Background
Object
FPS: — Speed: —
🔒 This tool runs entirely in your browser — your files are never uploaded to any server.

Hz & Ghosting Analyzer has two test modes: a refresh rate detector that measures your display's actual Hz using requestAnimationFrame timing, and a motion blur canvas test that lets you visually assess ghosting and pixel response on any monitor.

How to Use

  1. Click Detect Refresh Rate and keep the tab focused for 3 seconds. The tool measures the average interval between screen frames and maps it to the nearest standard Hz value.
  2. Check the detected Hz, average FPS, and frame time in the stats row.
  3. In the motion test section, choose a Speed, Background, and Object type, then click Play.
  4. Watch the moving object carefully. Trailing smears or duplicated edges indicate ghosting or slow pixel response.
  5. Switch backgrounds — Checker is the most revealing because the high-frequency pattern makes ghosting visible even at moderate speeds.
  6. Click Stop when done.

Options

  • Slow / Normal / Fast / Extreme — object speed in pixels per frame (2 / 4 / 8 / 16 px). At 60 Hz these equal roughly 120 / 240 / 480 / 960 px/s.
  • Dark — white object on dark background; ideal for IPS glow ghosting.
  • Light — dark object on light background; ideal for testing bright-background workflows.
  • Checker — high-contrast checkerboard pattern; the most sensitive for revealing ghosting trails.
  • Bar — sharp-edged rectangle; best for spotting trailing edges.
  • Ball — circle object; useful for evaluating motion clarity during curved movement.

FAQ

How accurate is the refresh rate detection?

Very accurate on most modern browsers. The tool samples several hundred frame timestamps over 3 seconds and averages the intervals, filtering out any spikes. The result is rounded to the nearest known standard (24 / 30 / 60 / 120 / 144 / 165 / 240 / 360 Hz).

What is ghosting on a monitor?

Ghosting is a visual artifact where a moving object leaves a faint trail or "ghost" image behind it. It is caused by slow pixel response time — the LCD panel cannot change pixel color fast enough to keep up with the refresh rate, so the previous frame partially bleeds into the next.

What is motion blur?

Motion blur is blurriness perceived on fast-moving content. On a display it has two sources: slow pixel response (same as ghosting) and the sample-and-hold nature of LCDs where each frame stays on-screen for the full frame duration, causing the eye to perceive blur as it tracks motion.

My detected Hz is lower than the monitor spec. Why?

Browsers may be throttled when the tab is not in focus, or the OS compositor may limit frame delivery. Make sure no other heavy process is running, keep the tab focused, and run the test again. Also, some browsers cap requestAnimationFrame to the system clock granularity.

Can this tool fix ghosting?

No. This is a diagnostic-only tool. Reducing ghosting requires adjusting the monitor's Response Time or Overdrive setting in its OSD menu. Some monitors also offer Motion Blur Reduction (backlight strobing) modes.

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