Stop the Clock

Visible timer counting up. Stop it as close to 10.00 seconds as you can.

Difficulty:EasyAvg:180 msPlays:92K

Press SPACE or click

How it works

A timer counts up from 0.00s on screen. Stop it as close to 10.00s as you can. Five rounds. Your score is the average absolute deviation from 10s, in milliseconds — lower is better.

Controls

Click or SPACE

Mouse and touch input also work.

Metric

avg deviation (ms)

Average

180 ms

Difficulty

Easy

Plays

92K

What Is a Good Stop the Clock Score?

The current BrainRivals average for this test is 180 ms. Use that as a baseline, then compare against your saved personal best and the public leaderboard for this specific test.

LeaderboardDaily routineRelated tools

What It Tests

Visual reflex precision and millisecond-level timing. Unlike Time Estimation (which hides the clock), this rewards how cleanly you can react to a number you can see ticking up.

How It Works

A timer counts up from 0.00s on screen. Stop it as close to 10.00s as you can. Five rounds. Your score is the average absolute deviation from 10s, in milliseconds — lower is better.

Why It Matters

Stopping a visible clock at a target measures the lag between perceiving a number and committing to an action. The same skill underlies racing-game lap timing, rhythm games, and any task where you have to react to a live readout.

Tips to Improve

  • 01Don't track the digits one-by-one — your eyes can't keep up past about 100ms intervals
  • 02Watch the second digit shift, not the third — that's the cleanest cue
  • 03Anticipate by ~80–100ms to compensate for click latency
  • 04Five short rounds means a single bad miss doesn't ruin your average

Next Tests

Hearing Test

Measure the quietest tones you can hear across six key frequencies.

Visual Acuity

Identify the direction of the gap in increasingly smaller circles.

Time Estimation

Stop the clock at the right moment. No counting, no peeking — just your internal sense of time.

Stop the Clock | Free Online Cognitive Test by BrainRivals