Reaction Time Test
Wait for the screen to turn green, then click as quickly as you can. The test reports the delay in milliseconds and keeps a running average and best result for up to 20 attempts in this browser session. Results vary with attention, practice, device and browser timing, so compare repeated attempts on the same setup rather than treating one number as a diagnosis or universal ranking.
How the test runs
-
1
Wait for the cue
The screen stays red while a random delay (1.5–4.5 s) plays. Clicking early voids the attempt.
-
2
React on green
As soon as the screen turns green, click anywhere. The timer is captured the moment you click.
-
3
Repeat a few times
A handful of attempts smooths out flukes: the first one is often slower as you warm up.
-
4
Read the average
The running average and best time update after every attempt. Use several runs on the same device for a steadier personal comparison.
How to interpret the result
Published studies report substantially different simple visual reaction times because protocols, participant groups and equipment differ. Large studies commonly place group averages in the low-to-high 200-millisecond range, but that is context rather than a pass/fail boundary. This browser test is not a medical, neurological, driving or sports-fitness assessment.
What the test measures
The recorded delay includes detecting the colour change, preparing and making the response, plus display, browser and input-device timing. Web timing can be consistent enough for repeated comparisons, but different systems introduce different offsets. A mouse, trackpad and touchscreen should not be compared as if they were identical instruments.
Getting a more useful comparison
- Run several attempts and use the average rather than a single best click.
- Keep the same browser, display, input device and posture between sessions.
- Avoid anticipating the cue; early clicks are rejected and immediately restartable.
- Test when you can concentrate. Sleep loss can impair reaction-time performance, but the size of the effect varies.
- Treat caffeine, practice and age claims cautiously: study results depend on dose, task and population, and this tool cannot explain why your result changed.
Frequently Asked Questions
Attention, anticipation, hand position and device timing all vary from attempt to attempt. Use several runs and rely on the average rather than one unusually fast or slow click.
Yes. Display refresh, browser scheduling and the input device all contribute to the recorded delay. Compare results on the same setup instead of treating scores from different devices as equivalent.
The attempt is marked too soon and is not included in your results. Click the panel again to begin a fresh random wait.
No. It is a casual browser measurement, not a medical or safety assessment. Seek qualified advice if you have concerns about sudden or persistent changes in your reactions.
No. Each run stays in your browser tab. Closing it clears the attempt data.
Related Tools
Mouse Tester
Test your mouse buttons, wheel scrolling, pointer movement and double-click timing in the browser. See event logs and movement samples without uploads.
Spacebar Counter
Count distinct spacebar presses or run a timed test with a target, timer, progress and presses-per-second estimate.
Fancy Serial Number Checker
Check US-style currency serial numbers for fancy patterns like radars, ladders, repeaters, low numbers and star notes.
Competition Bracket Maker
Build a seeded or shuffled single-elimination bracket for 2–32 teams or players, assign automatic byes, advance winners, copy and print it.
Minecraft Circle Generator
Create hollow or filled Minecraft circle and ellipse blueprints. Set the block dimensions, count materials, inspect the grid and download an SVG.
Metronome
Practice with a precise online metronome. Set BPM, meter, accent and subdivisions, then play a steady browser click locally.