Reaction Time Test
PopularUtility Tools
Measure your visual reaction time in milliseconds (ms) using high-resolution timers. Features randomized delays, false-start detection, and multi-trial statistical tracking.
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How to Use Reaction Time Test
Use the controls above, then check the example and limitations below.
Arm the Test
Click or tap the test surface to start the randomized waiting period.
Wait for the Green Signal
Wait for the screen to turn green and display 'CLICK NOW!'. Clicking early triggers a false start.
Respond Instantly
Click anywhere or press Spacebar as quickly as possible to record your reaction time.
What is Reaction Time Test & How Does It Work?
The Reaction Time Test measures visual response time in milliseconds (ms) using high-resolution browser monotonic timing.
Using the performance.now() API, the test presents an unpredictable randomized delay before triggering a visual signal. Responding as soon as the signal appears measures the interval between stimulus presentation and user input.
The test tracks best and average times across multiple attempts to reduce variance. Results reflect visual response combined with computer display refresh latency and input device polling.
Key Features & Benefits
High-Resolution Monotonic Timing
Utilizes performance.now() to measure response duration accurately without wall-clock drift.
Multi-Trial Average
Computes running average and best reaction time across valid attempts.
False-Start Protection
Detects premature inputs during randomized wait windows to enforce valid measurements.
Client-Side Processing
Runs entirely in browser memory with zero network latency and complete privacy.
Common Use Cases
Focus & Alertness Tracking
Observe variations in reaction speed across different times of day or fatigue levels.
Display & Input Comparison
Assess responsiveness differences across different mouse, keyboard, or display hardware setups.
Personal Benchmarking
Track personal response time trends over multiple repeated attempts.
Frequently asked questions
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