Input Lag Test

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Category System & Hardware

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Rapid clicks allowed • Press SPACE for keyboard test

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Last Latency

-- ms

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Average (Mean) --

Min / Max -- / --

Jitter (σ) --

1% Lows (Worst) --

Samples 0

Latency Distribution (Histogram) Good Bad

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About

This tool quantifies the End-to-End System Latency (in Camera Mode) or the Browser Processing Latency (in Software Mode). In high-performance computing and competitive gaming, input lag is the critical delay between a physical actuation (mouse click) and the corresponding visual feedback (photon emission).

Unlike basic stopwatches, this engine utilizes the performance.now API with microsecond precision, coupled with a statistical engine that calculates not just the mean, but the standard deviation (jitter) and the 99th percentile lows. This is crucial for detecting micro-stutters that average latency figures often hide.

The measurement pipeline follows this rigorous path:

T_total = T_peripheral + T_usb + T_os + T_render + T_display

For software developers, this tool exposes the overhead of the Main Thread. For gamers, it helps isolate whether a "sluggish" feeling is due to network conditions (ping) or local hardware bottlenecks (input lag).

Formulas

We calculate the statistical variance (Jitter) to determine the stability of your connection. High jitter indicates background processes fighting for CPU time or USB polling instability.

Jitter = √n∑i=1 (x_i − x)²n − 1

We also track the Frame Time Floor, which is the theoretical minimum latency possible given your monitor's Refresh Rate (Hz).

T_min = 1000Hz

Reference Data

Hardware Tier / Component	Refresh Rate (Hz)	Frame Time (ms)	Exp. System Latency (ms)	Status
CRT Monitor (Analog)	85-120	8.3-11.7	< 5.0	LEGENDARY
OLED 360Hz (eSports)	360	2.78	8 - 12	GODLIKE
TN/Fast-IPS 240Hz	240	4.17	12 - 18	COMPETITIVE
IPS Gaming 144Hz	144	6.94	20 - 30	EXCELLENT
Standard Office (60Hz)	60	16.67	45 - 60	STANDARD
TV (Game Mode ON)	60	16.67	30 - 50	VARIES
TV (Game Mode OFF)	60	16.67	80 - 150	POOR
Mouse: Optical Switch	N/A	N/A	0.2 - 0.5 (Click only)	INSTANT
Mouse: Mechanical Switch	N/A	N/A	4.0 - 8.0 (Debounce)	FAST
Bluetooth Peripheral	N/A	N/A	+15 - 40 (Added)	LAGGY
Cloud Gaming (Streaming)	60	16.67	80 - 200	HIGH

Frequently Asked Questions

If your latency results are consistently multiples of 16.6ms (e.g., 33.2ms, 49.8ms) on a 60Hz screen, your browser or OS is enforcing Vertical Synchronization. This queues frames to prevent screen tearing but adds significant input lag. Disable "V-Sync" in your GPU driver or browser settings for accurate raw measurements.

Software Mode measures the time from the Browser Event (JS) to the Paint Frame. It isolates the software stack. Camera Assist Mode displays a frame counter and color code. You must record your screen with a high-speed camera (240fps+ phone) and count the physical frames between your finger hitting the mouse and the screen changing color. Camera Assist measures the TOTAL reality of lag.

1000Hz means the mouse reports every 1ms. However, the signal must travel through the USB controller, the OS Kernel, the Window Compositor (DWM/Quartz), the Browser Engine, and finally the Display scalar. 20ms is actually a very good result for a browser-based test running on a standard 60-144Hz desktop.

Yes. Touch devices often have higher latency than mice due to "Touch Sampling Rates" (often 120Hz or 240Hz) and gesture processing. Use the "Zen Mode" to test tap-to-photon latency.

Jitter (Standard Deviation) should be as close to 0 as possible. < 2ms is professional grade. 2-5ms is standard. > 10ms implies your computer is freezing, background apps are interfering, or you have a faulty cable.