Online Metronome

What a metronome does, and what a click track means

The word comes from two Greek roots meaning measure and law, and that is a fair description: a metronome lays down a rule for how long a beat lasts, and you play against it. Early ones were wooden pyramids with a swinging weight on a rod, wound like a clock. Today the same job is done by a few lines of code and a short burst of sound.

In a recording studio the same idea is called a click track. Drummers and bands often play with a click in their headphones so that every take is at the same tempo, which makes it simple to edit, layer and combine takes afterwards, and to line up electronic parts such as samples and synths. When someone says they are recording to a click, they mean exactly what you hear from this page: an even, accented pulse that only the performer hears.

Click tracking is also how most practice works. The metronome is not there to make music sound mechanical; it is there to show you where you rush and where you drag. Almost everyone speeds up through easy passages and slows down through hard ones, and the click makes that visible at once.

A beat has no meaning until you pick the tempo, so the first decision is the number. If you are learning a song, find its speed with the BPM finder or tap tempo, and open the result here. If you are writing your own piece, choose a tempo word from the table in the Numbers tab and adjust by feel.

The controls, one by one

The tempo range is 20 to 300 BPM. Drag the slider for a rough setting, nudge it with the plus and minus buttons by one, or jump by five with the larger ones. The one-step buttons are for fine adjustments when you are matching a recording; the five-step buttons suit practice, where you move up in small but noticeable stages. A Volume slider sets the click level. There is no box for typing a BPM; use the slider, the buttons or tap tempo, or open a link such as /metronome/#bpm=96 from another tool.

Beats per bar offers 1 to 9 and 12, which covers the common signatures: 4 for most pop and rock, 3 for waltzes, 6 for compound feels, 5 and 7 for the odd meters that keep drummers busy. The accent on beat 1 gives the first click of each bar a stronger sound, so you always know where the bar begins. Turn it off for a plain, even pulse, which is good when you want to feel the music without a marked downbeat.

Three sounds are available. Click is a short, dry tick that stays out of the way. Woodblock has a rounder tone that cuts through an acoustic instrument. Beep is a clear pitched tone that some players find easier to hear over loud playing.

Visual beat dots show the position in the bar. The current beat lights up, one dot per beat in the bar. This is useful in a noisy room, or when you are playing something where you cannot rely on hearing the click clearly. Tap a dot to cycle that beat between accent, normal and silent, which lets you build a bar like loud, soft, silent, soft.

A tap tempo button is built in as a convenience. Tap a few times to set the speed from the feel of a song. For a longer look at how the averaging behaves, the full tap tempo page shows the evenness of your taps.

How to practice with a metronome

The most useful habit is to start slower than you think you need. Take a passage you cannot yet play cleanly and set the metronome to a speed where you can play it without a single mistake, even if that is half the target tempo. Play it correctly three times in a row. Only then move up.

The step ladder works like this: raise the tempo by 5 BPM, repeat the passage cleanly, and raise it again. When you fail, go back one rung rather than pushing on. Use the plus five button for each rise. A passage that is 80 BPM away from your goal takes sixteen rungs, which sounds long but can be done in a single focused session, and the result lasts far better than a rushed run at full speed.

Do not let the click do all the work. Once a part feels comfortable, try placing the click on beat 1 only, then only on beats 2 and 4, then turn it off for a bar and see if you are still together when it returns. Playing in time without an audible click is the real goal, and the click is the scaffolding that gets you there.

Keep sessions short. Ten to fifteen minutes on one hard passage, with a break, does more than an hour of tired repetition. Write down the tempo you reached so that tomorrow you start there, not from memory.

If you are using headphones, keep the level comfortable. A click is sharp and repeats thousands of times, so a moderate volume protects your ears over a long practice session. The Speed trainer raises the tempo for you: it adds N BPM every M bars until a maximum you set, which suits working a passage up toward performance speed. While the metronome runs, the page asks the browser to keep the screen awake where that is supported.

Subdivisions: counting the spaces between the beats

A subdivision splits each beat into smaller equal parts and clicks on them quietly between the main beats. Quarter means no subdivision: one click per beat. Eighth splits the beat in two, so the count goes one-and, two-and. Triplet splits it in three, giving one-trip-let. Sixteenth splits it in four, one-e-and-a.

The point is to hear the grid your notes should sit on. If you are learning a fast run of sixteenth notes, a click on only the beat leaves three notes in four unchecked, and it is easy to hurry them. With the sixteenth subdivision on, every note has a click to land on.

Triplets are the key to shuffle, swing and many blues and jazz grooves, as well as the lilt of compound meters. Switching a metronome from eighths to triplets at the same BPM is an instructive experiment: the main beat does not move, but the feel changes from straight to rolling.

A good routine is to practice a part at a slow tempo with sixteenth clicks, and then at a faster one with eighths, then at the target tempo with just the beat. The subdivision does not need to be loud; the main beats and the accent stay the strongest, and the small ones serve as a quiet guide.

Tempo words and beat length

Before the metronome was invented, composers wrote Italian words at the top of a piece to describe its pace. The table in the Numbers tab gives the usual BPM ranges for the common ones: largo is broad and slow, andante is a walking pace, allegro is lively, and presto is very fast. The ranges overlap, and different sources draw the lines in slightly different places, so treat them as guides.

Beat length is the same information in time rather than count. A beat at 60 BPM lasts exactly one second. At 120 BPM it is half a second, and at 240 BPM a quarter of a second. The formula is 60,000 divided by the BPM, which gives milliseconds.

If a piece is marked with a quarter note equal to 72, set 72. If it is marked with a dotted quarter, set the BPM to the dotted quarter. For pieces in 6/8, many players set beats per bar to 2 and the subdivision to Triplets, so each main click is one big beat of two and the quiet clicks mark the eighth notes.

Why a browser metronome needs audio-clock scheduling

A metronome seems trivial to build: wait 500 milliseconds, play a sound, repeat. The simple version fails because web pages share one busy thread with everything else. A timer that asks for 500 milliseconds can fire 505 one time and 520 the next, whenever the page is also drawing, loading or handling a tap. Each late click is small, but you can hear the unevenness, especially in subdivisions.

The fix is to use the audio clock. The browser's audio system keeps its own very steady time, and it lets a program schedule a sound for an exact moment in the future. Here, the page looks ahead by a short interval and tells the audio system when each upcoming click should sound. A rough timer only needs to wake up often enough to keep the schedule filled, so its small delays no longer reach your ears.

In practice, this means timing runs on the audio clock instead of the page's timers. The beat dots are drawn to match the schedule, and the sound itself does not wait on the screen. You can scroll, tap other buttons or change the tempo without making the click stutter.

Some limits remain. On a phone, locking the screen or switching apps may pause audio in the browser, so keep the page open while you play. Bluetooth headphones add a delay of their own, often noticeable in the tens or hundreds of milliseconds. The click will still be even, but it can arrive late compared to your hands. A wired connection avoids it.

Phone, desktop and privacy

The page works on phones, tablets and computers, and the space bar starts and stops it on a keyboard. On a phone, check that the silent switch or media volume is not muted, since a metronome with no sound is a common surprise.

Nothing is installed, and no sound is recorded or sent anywhere. There is no microphone request, because the page only produces sound and has no need to listen. Links from the BPM finder and tap tempo can set the tempo for you, and the address can carry a tempo, for example /metronome/#bpm=96, which is how those links work.