How does the mouse accuracy test score me?

In Click targets mode a press inside the current target is a hit and a press anywhere else in the arena is a miss; the target stays until you hit it. Accuracy is hits divided by hits plus misses. Each hit gets an interval, from the press that revealed the target (the start ring or your previous hit) to the press that hit it, and a distance from the centre of the target. Points are 1000 minus 20 per miss minus the total time in tenths of a second, never below 0: 30 targets cleared in 24.6 s with 2 misses give 1000 minus 40 minus 246 = 714 points. Presses outside the arena and right-button presses do not count.

How accurate is the timing?

Every interval is the difference between two pointer events' own timestamps on the browser's performance clock, so a delay that stays the same from press to press, such as your mouse or touchscreen input lag, cancels out. The time your screen takes to draw each new target stays in, because you cannot react to a target before it appears, and the browser cannot report that display lag. Some browsers round event timestamps to a millisecond or coarser. The figures compare your own sessions on one device; they cannot measure your hardware's latency, assess motor ability or rank you against other people.

What does tracking mode measure?

Track a target moves one target in straight lines that bounce off the arena edges and turn in a new seeded direction every 1.5 seconds, at 60, 120 or 200 units per second. Every animation frame compares where the browser last reported your pointer with where the target is drawn in that frame. On target is the share of the session your pointer spent inside the target; mean path error is the average distance from the target's centre while your pointer was in the arena, weighted by time; pointer away is the time it was outside the arena or, on a touch screen or pen, lifted. A per-second chart and table show how it changed through the session.

What happens if I switch tabs or pause?

Hiding the tab, the browser window losing focus or pressing Pause stops the clock and hides the target until you press Resume. The paused time is left out of every interval, and the session is labelled interrupted: it still shows its results and joins your sessions, but it is never scored as a challenge. End session or Escape stops early; an ended session shows what you did so far but is not scored or saved.

How does the aim challenge link work?

New challenge opens a fixed configuration: 30 static targets, 40 units across, at places set by a random seed. Pressing the start ring starts the clock and the 30th hit stops it. If you finish your first session of those targets without a pause, you can copy the challenge link, share it or download a result card. Your friend sees your self-reported score and the rules and presses Start same challenge; nothing starts by itself. They get the same targets in the same order, and afterwards the page shows both scores, the signed difference and a new link carrying their score. Replays, paused or hidden-tab sessions, ended sessions and targets this browser has already shown are practice. Besides the tool name, the link holds only the seed, the 30-target setting and the score.

Can I use it on a phone, or with a keyboard?

On a phone or tablet, tap each target with a finger, and in tracking mode keep your finger on the moving target. The arena scales to fit the screen, so a Small target is small on a narrow phone; choose Large there. Aiming needs a pointer, so the arena cannot be played with keys, but every button and setting works from the keyboard, Escape ends a session, and every chart has a table with the same figures. Buttons and fields are at least 44 pixels tall.

What is saved in my browser?

Settings you change, your last 20 completed sessions with their results, and the seeds of up to 1,024 click sessions whose targets this browser has shown, all under one local storage key. Your presses, positions and times are not sent anywhere. Practice again reopens a past session with the same settings and seed as practice. A session in progress is never restored.

Mouse Aim Practice

Practice aim with targets that appear one at a time in a 480 by 360 arena that scales to fit your screen. Click targets mode puts each target at a place set by a seed, standing still or drifting at one of three speeds, and records hits, misses, the interval to every hit and how far from the centre you pressed. Track a target mode moves one target for 15, 30 or 60 seconds and measures how much of the time your pointer stayed on it and its mean path error. Each completed session is compared with your previous one on the same settings when there is one, hiding the tab pauses the clock and labels the session interrupted, and a fixed challenge of 30 static targets can be shared as a link so a friend can try the same targets in the same order.

SettingsUsed by Start practice

Target sizeSpeedTargetsSeed

The arena is 480 by 360 units and scales to fit your screen, so targets shrink and grow with it. The same seed and settings always give the same targets, a longer session continues the same sequence, and in Click targets mode size and speed never change where targets appear. New challenge ignores these settings: it is always 30 static Medium targets.

ArenaNo session open

Press Start practice to open the arena.

Aiming needs a mouse, trackpad, pen or touch screen. Every button and setting works from the keyboard, and Escape ends a session, but the arena itself cannot be played with keys: moving a focus from target to target would not be aiming.

Preparing.

Your sessions

Finished sessions appear here, newest first, and stay in this browser. Up to 20 are kept, and each new one is compared with your previous session on the same settings.

Miss25 units from the centre
A 40-unit target has a 20-unit radius, so a press 25 units from its centre is a miss, and one exactly 20 units away is a hit.
Mean interval412, 388, 455, 390 ms
Four hits with those intervals average 411.3 ms.
Challenge points24.6 s, 2 misses
30 targets cleared in 24.6 s with 2 misses: 1000 minus 40 minus 246 = 714 points.
Interruptedtab hidden 4 s in
The session pauses, the time away is left out of every interval, and the result is labelled interrupted and never scored.

Common questions

How does the mouse accuracy test score me?: In Click targets mode a press inside the current target is a hit and a press anywhere else in the arena is a miss; the target stays until you hit it. Accuracy is hits divided by hits plus misses. Each hit gets an interval, from the press that revealed the target (the start ring or your previous hit) to the press that hit it, and a distance from the centre of the target. Points are 1000 minus 20 per miss minus the total time in tenths of a second, never below 0: 30 targets cleared in 24.6 s with 2 misses give 1000 minus 40 minus 246 = 714 points. Presses outside the arena and right-button presses do not count.
How accurate is the timing?: Every interval is the difference between two pointer events' own timestamps on the browser's performance clock, so a delay that stays the same from press to press, such as your mouse or touchscreen input lag, cancels out. The time your screen takes to draw each new target stays in, because you cannot react to a target before it appears, and the browser cannot report that display lag. Some browsers round event timestamps to a millisecond or coarser. The figures compare your own sessions on one device; they cannot measure your hardware's latency, assess motor ability or rank you against other people.
What does tracking mode measure?: Track a target moves one target in straight lines that bounce off the arena edges and turn in a new seeded direction every 1.5 seconds, at 60, 120 or 200 units per second. Every animation frame compares where the browser last reported your pointer with where the target is drawn in that frame. On target is the share of the session your pointer spent inside the target; mean path error is the average distance from the target's centre while your pointer was in the arena, weighted by time; pointer away is the time it was outside the arena or, on a touch screen or pen, lifted. A per-second chart and table show how it changed through the session.
What happens if I switch tabs or pause?: Hiding the tab, the browser window losing focus or pressing Pause stops the clock and hides the target until you press Resume. The paused time is left out of every interval, and the session is labelled interrupted: it still shows its results and joins your sessions, but it is never scored as a challenge. End session or Escape stops early; an ended session shows what you did so far but is not scored or saved.
How does the aim challenge link work?: New challenge opens a fixed configuration: 30 static targets, 40 units across, at places set by a random seed. Pressing the start ring starts the clock and the 30th hit stops it. If you finish your first session of those targets without a pause, you can copy the challenge link, share it or download a result card. Your friend sees your self-reported score and the rules and presses Start same challenge; nothing starts by itself. They get the same targets in the same order, and afterwards the page shows both scores, the signed difference and a new link carrying their score. Replays, paused or hidden-tab sessions, ended sessions and targets this browser has already shown are practice. Besides the tool name, the link holds only the seed, the 30-target setting and the score.
Can I use it on a phone, or with a keyboard?: On a phone or tablet, tap each target with a finger, and in tracking mode keep your finger on the moving target. The arena scales to fit the screen, so a Small target is small on a narrow phone; choose Large there. Aiming needs a pointer, so the arena cannot be played with keys, but every button and setting works from the keyboard, Escape ends a session, and every chart has a table with the same figures. Buttons and fields are at least 44 pixels tall.
What is saved in my browser?: Settings you change, your last 20 completed sessions with their results, and the seeds of up to 1,024 click sessions whose targets this browser has shown, all under one local storage key. Your presses, positions and times are not sent anywhere. Practice again reopens a past session with the same settings and seed as practice. A session in progress is never restored.

Intervals are differences between the browser's own pointer-event timestamps, so a steady mouse or touch delay cancels out, but the time your screen takes to show each target stays in. Tracking error compares where the browser last reported your pointer with the target drawn in each frame, so pointer and display lag add to it. This is recreational practice: browser events cannot establish hardware latency, clinical motor ability or a population ranking.