What a reaction time test measures
This reaction time test measures the delay between a visual stimulus on your screen and your physical click response. The test registers the exact millisecond you click after the background color changes from blue to green. This measurement combines your physical mental processing speed with your computer's system latency.
1. Monitor frame latency
A standard 60Hz monitor displays one frame every 16.6ms. A fast 240Hz screen drops this frame-generation delay to just 4.1ms, allowing you to see the green transition faster.
2. Peripheral polling rate
Standard USB mice poll the OS at 125Hz (8ms delay). A specialized gaming mouse polling at 1000Hz drops signal transfer delay to just 1ms, resulting in cleaner scores.
3. Input processing lag
Monitor panels perform internal image processing (scaling, contrast boosters). Game modes or VRR settings (like G-Sync) disable this processing, bypassing 10-30ms of extra lag.
Reaction time vs input lag
Reaction time and input lag measure different delays. Human reaction time is the biological speed at which your brain and muscles process a visual signal. The average biological reaction speed to visual cues is around 250 milliseconds.
Input lag refers to the hardware and software delay in your display system. This includes the time your monitor takes to draw a new frame and the time your mouse takes to report a click. Therefore, your score shows the combined total of human reflexes and hardware delays.
Why browser and device delay matter
Your browser engine and operating system introduce minor delays when rendering colors and processing click events. A browser-based test registers slightly slower scores than professional medical hardware. Display latency and driver overhead also add a few milliseconds to your final score.
Different devices show varying latency characteristics. For example, testing on a mobile phone touch screen usually produces slower scores than using a wired USB mouse on a desktop computer. This variation is caused by touch digitizer polling rates and mobile system power-saving states.
How to get a fair result
To get the most accurate and consistent score, you should minimize external hardware delays. A wired mouse reduces signal transmission latency. You should also close background programs to prevent CPU spikes from affecting browser performance.
You should also check that your monitor is set to its native resolution and maximum refresh rate. If your display supports a dedicated game mode or instant response setting, enable it before starting the test. These configurations reduce display latency by disabling unnecessary image processing.
What average results usually mean
An average result on a standard 60Hz display is typically between 200ms and 280ms. If you score under 200ms, you have fast reflexes or are using high-end gaming hardware. Scores above 300ms can indicate temporary fatigue, a slow wireless mouse, or high display input lag.
Testing yourself multiple times helps calculate a reliable average. Reflexes naturally vary based on sleep, distraction, and the time of day.
Related tools and guides
If you want to check your display for other performance characteristics, you can browse our collection of display tools. To check for display smearing or slow pixel response times, try our monitor ghosting test. You can also read our refresh rate guide to understand how frame speed affects latency.