Browser timing, shown honestly

Reaction timing without the black box.

A lean visual and audio reaction-time test that reports the timing uncertainty alongside every score — tuned for high-refresh displays up to 600 Hz.

Visual: 5 trials · audio: 10 cues · no sign-up

±0.8 ms
Visual confidence at 600 Hz
128 KB
Rust scoring core (WASM)
2
Modalities · audio + visual
0
Hidden error bars
01Method

What makes the number honest.

A

Painted-frame visual timing

Visual stimuli are timestamped at the frame we actually paint — inside requestAnimationFrame — not the frame we asked for. Confidence scales with your display: about ±8.3 ms at 60 Hz and ±0.8 ms at 600 Hz.

B

Honest about audio

Browser audio output latency is unknowable to the millisecond — and brutal on Bluetooth. We label audio results as relative, warn on wireless, and never pretend an absolute number is exact.

C

A scoring core you can audit

Stats, percentiles and anti-cheat run in a small Rust core compiled to WASM — the same code on your device and on our server, so the leaderboard re-scores every run from raw trial data.

Read the full methodology →

02Training arenaBeta

Train the reflex.

A 3D reaction, aim, and decision training suite — a Rust/Bevy engine that loads only when you play. Every run is seed-derived and re-scored server-side by the same core as the precision tests: raw milliseconds, ± bands, and per-action cursor metrics, all browser-observed.

Training-grade, same-setup competition. It complements the precision reaction-time test — it doesn't replace it.

Enter the Arena →Beta · ranks provisional
Flick GridAIM · FITTS

Targets pop, you snap — aiming throughput per second.

Lock-OnTRACK · PURSUIT

Glue the reticle to a target that won't hold still.

Snap DecisionCHOICE · HICK

Right answer, right now — the cost of choosing.

Bomb SquadGO / NO-GO

Cut the wire on go, hold on the bomb — how well you stop.

FocusFLANKER

Read the center arrow while the flankers scream the opposite — focus under noise.

Fitts throughput · d′ · drift rate · path efficiency — every metric with its uncertainty

Find your baseline.

Visual ranks by median. Audio ranks by 10-cue average. Both keep uncertainty visible.