About ReflexTester.fun
We're a small team of competitive gamers, web developers, and cognitive performance enthusiasts who got tired of paying for tools that should be free. So we built them ourselves.
Our Story
ReflexTester.fun started in 2023 as a side project. We were frustrated that the best reaction time testing tools were either locked behind paywalls, riddled with ads, or scientifically inaccurate. Most browser-based testers had input lag of 20-50ms baked in and never mentioned it.
We spent months researching reaction time science — reading studies from the Journal of Motor Behavior, sports psychology research, and esports performance labs — before writing a single line of code. The result is a platform where every tool is built around one principle: accurate measurement first, everything else second.
Today, ReflexTester.fun hosts 31+ free tools used by competitive gamers, athletes, coaches, physical therapists, researchers, and anyone curious about their own cognitive performance. We have never charged a single cent and we never will for core features.
Why Reaction Time Matters
Reaction time is the time elapsed between a stimulus and your voluntary response to it. It sounds simple, but it sits at the intersection of neuroscience, motor learning, and athletic performance. Your reaction time is a real, measurable indicator of your nervous system's efficiency.
In competitive gaming, a 50ms improvement in reaction time is the difference between landing a shot and getting eliminated. In driving, a 100ms improvement is roughly 3 metres of stopping distance at highway speeds. In medical settings, reaction time decline is an early biomarker for conditions like Parkinson's, concussion, and cognitive aging.
The science is clear: reflex speed is trainable. Regular, deliberate practice using the right protocols can improve reaction time by 40-80ms in most healthy adults, regardless of age or starting point. The key is measuring accurately so you can train intelligently and track real progress — not guesswork.
How Our Tools Work
Every test on ReflexTester.fun uses performance.now() — a high-resolution timer
accurate to fractions of a millisecond in modern browsers — instead of the imprecise
Date.now() used by most websites. This eliminates the 15-60ms measurement error common
on other platforms.
| Test Type | What It Measures | Who It's For |
|---|---|---|
| Visual Reflex Test | Simple visual reaction time (stimulus to click) | Gamers, drivers, athletes |
| Audio Reflex Test | Auditory reaction time (sound to keypress) | Musicians, sprinters, martial artists |
| Click Speed (CPS) | Peak clicks-per-second throughput | FPS gamers, competitive clicking |
| Aim Trainers (CS:GO, Valorant, etc.) | Mouse accuracy and tracking under movement | Esports players, aim practice |
| Memory Sequence Test | Working memory capacity and visual-spatial recall | Cognitive health, students, researchers |
| Typing Speed Test | Words-per-minute at sustained accuracy | Developers, writers, administrative professionals |
| Stroop Effect Test | Cognitive interference and inhibition control | Psychology research, cognitive training |
| Peripheral Vision Test | Visual field awareness and detection speed | Drivers, ball sport athletes, pilots |
On-Device Privacy
All your test results are stored locally in your browser's localStorage. Nothing is sent to our servers. Your scores, history, and personal bests live on your own device and are never shared with us or third parties. You can clear them anytime from the Dashboard page.
Our Values
Free Forever
All 31+ tools are completely free. No premium tier, no credit card, no sign-up. We mean it.
Scientifically Grounded
Every tool is built from peer-reviewed research. Our blog articles cite real studies and explain the science clearly.
Privacy First
Your data stays in your browser. We collect only anonymous analytics to understand which tools are most used.
Accuracy Over Hype
We use sub-millisecond timing APIs. We document methodology. We show benchmark comparisons. No inflated scores.
Universal Access
Works on any device with a modern browser. No downloads, no plugins, no setup. Open it and go.
Honest Content
Our blog covers the real science of reaction time — including what doesn't work, not just what makes headlines.
What We're Working On
ReflexTester.fun is actively developed. Upcoming features include:
- Percentile benchmarks — see how your score compares to aggregated, anonymised data from other users in the same age range
- Training protocols — structured 30-day programs for improving specific reaction time types, backed by motor learning research
- Mobile app — a lightweight Progressive Web App version for offline training
- Custom test builder — configure stimulus timing, catch trials, and response modality for research and coaching use cases
Content Philosophy
Every article on this site is written by our editorial team — people who have personally spent hours testing the methods they write about. We read the original studies, not just press releases. We cite our sources. We distinguish between what the research shows and what is speculative.
We believe that the best information about reaction time and reflexes should be freely available to everyone — not locked inside academic journals or expensive coaching programmes. That is why we invest heavily in long-form, evidence-based content alongside our tools.
Get in Touch
Found a bug? Have a feature request? Conducting research and want to collaborate? We genuinely read every message and reply within a few days. You can also email us directly at hello@reflextester.fun.