Reaction time test: what’s normal, and how to get faster

Reaction time is the gap between something happening and you responding to it. Here’s what affects it, what counts as fast, and how the tests in Reactdle measure it.

What is reaction time?

Even the simplest reaction, a light coming on and a button press, is a chain: your eyes register the change, the signal travels to the visual cortex, your brain decides to act, and a command travels down to the muscles in your hand. Each step takes time, which is why nobody reacts instantly.

What’s a good reaction time?

In lab studies, young adults usually react to a simple light in roughly 200 to 250 milliseconds. Online tests tend to read a little slower, often 250 to 300 ms, because the screen and the mouse or touchscreen add their own delay. A 60 Hz screen only redraws every 16.7 ms, and touchscreens typically add more lag than a mouse.

Sound is processed faster than sight, so people respond to a beep a few tens of milliseconds sooner than to a light. That’s why Reactdle never signals with sound: every test is visual, so results are fair.

Different kinds of reaction

Simple reaction time is one signal and one response, like Wait for Green or the F1 start lights test. Choice reaction time adds a decision, like the Go / No-Go test, which also measures holding back.

Aiming adds movement: the time to hit a target grows with how far away and how small it is (Fitts’s law), which Targets and Skeet measure. Thinking tasks add a conflict to resolve first, like the Stroop test and the flanker test. Timing tasks, like Stop the Clock, measure your internal clock instead of speed.

What makes you faster or slower

• Sleep matters most. Being tired reliably slows reactions and makes them less consistent.
• Age. Reaction time is quickest in early adulthood and slows gradually after that.
• Warming up helps a lot: the first few tries of the day are usually the slowest.
• Caffeine can help a little.
• Practice improves choice tasks far more than it improves pure reflexes.
• Your device. A mouse on a fast monitor will usually beat a phone screen, so compare yourself on the same device.

How to improve your reaction time

Short, regular practice beats long sessions. A daily set of varied tests, like Reactdle’s five, trains spotting signals, deciding and moving, rather than just one reflex. Get enough sleep, warm up with a practice round, and keep your finger close to the screen or key.

Try it

Reactdle gives everyone the same five tests each day, one each of reflex, aim, brain, timing and words, and shows how you compare with today’s other players.