Perfect rhythm for your music practice
This metronome uses the Web Audio API with a lookahead scheduler: instead of firing each click at the exact moment, it computes the times of upcoming beats in advance and schedules them on the system audio clock (AudioContext.currentTime), independent of the browser's rendering loop. That ensures stable timing even when the tab is in the background or the computer is busy. The beat-1 click (the accent) is differentiated by frequency and amplitude, so you can feel the start of each bar. The on-screen pendulum is synchronized with the audio, giving reliable visual feedback of the tempo. It covers 20 to 300 BPM, with 2, 3, 4, or 6 beats per bar, optional swing, and a Tap Tempo to find a song's BPM by tapping the rhythm.
A metronome's precision depends on the clock that drives it. JavaScript's setInterval is imprecise for music: under load it can vary by tens of milliseconds, enough to make the click sound like it's 'wobbling'. The Web Audio API solves this with a high-resolution audio clock, accurate to under a millisecond, that runs separately from the interface.
The technique used is the lookahead scheduler: a lightweight timer wakes up periodically, looks a small interval ahead and schedules on the audio clock every beat that falls within it. So even if the interface stutters, the clicks are already locked into the sound hardware and play at the exact time.
Example 1, training subdivisions. To practice eighth notes (two notes per beat) at 80 BPM, set the metronome to 160 BPM: each click now marks a subdivision, and you play at double the resolution without changing the song's real tempo. The same trick works for triplets (multiply by 3) and sixteenth notes (by 4).
Example 2, finding the BPM and feeling the bar. Use Tap Tempo by tapping along with a recording: the tool averages your last taps and shows the approximate BPM. Then, to play a waltz, choose 3 beats per bar and the accent on beat 1 marks the characteristic 'one-two-three' of 3/4 time.
Practice pays off more when you start slow. Pick a BPM where you can play the passage without mistakes (often 60–80), master it, and only then move up in steps of 5. Alternating between playing with and without the metronome helps develop your internal sense of time, rather than depending on the click.
One practical limit is the audio output: Bluetooth headphones and speakers add latency (a small delay) because of the wireless transmission. The internal clock stays accurate, but the sound arrives a moment later; for the smallest possible delay when recording or playing along, prefer wired headphones. The classic tempo markings serve as a reference: Largo (40–60), Andante (76–108), Allegro (120–168) and Presto (168–200).
Paste the code into your HTML and the tool shows up on your page, without J-Kit's navigation and ads. It still runs in the browser of whoever visits your site.
<iframe
src="https://jkit.tools/embed/en-US/metronome"
width="100%"
height="600"
style="border:0"
loading="lazy"
title="Online Metronome"
></iframe>These references help contextualize formulas, standards, APIs and limitations used on this page. They do not replace professional validation when a result has legal, financial, medical or operational impact.
BPM stands for beats per minute. It is the standard measure of musical tempo. 60 BPM = one beat per second. 120 BPM = two beats per second. Common tempos: Largo (40–60), Andante (76–108), Allegro (120–168), Presto (168–200).