Virtual Piano

A three octave piano from C3 to C6 you can play by mouse or computer keyboard, with sustain, note labels and two demo songs with falling note hints.

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OctaveKeyboard starts at C4

Click or tap a key, or play with your computer keyboard: A S D F G H J K for white keys, W E T Y U for the black keys in between, Z/X to shift which octave the keyboard maps to.

Demo songs

Watch the small bars above the keys — each one falls toward its key as the note approaches, then flashes when it plays.

🔒 Private by design: everything runs locally in your browser and never uploaded to any server.

Written and maintained by Last updated

A keyboard when there is no keyboard

The reasons to want a piano on screen are mostly small and practical. Checking what a chord sounds like while writing something down. Finding the melody you have stuck in your head. Playing a reference note for a singer. Showing a child which key is middle C. None of them justifies owning an instrument, and all of them are frustrating without one.

This page gives you three octaves that respond to a mouse, a touchscreen or your computer keyboard, with the note names available on the keys if you want them.

Playing it

  1. Click or tap any key, or use your computer keyboard.
  2. The home row from A to K plays white keys and W E T Y U play the black keys between them.
  3. Press Z or X to move the mapped range down or up an octave. The starting note is shown on screen.
  4. Turn on Sustain to let notes ring after you release them.
  5. Turn on Show note labels if you are learning where the notes sit.
  6. Pick a demo song to watch the falling hints and play along.

The keyboard mapping is a physical analogy

The computer key layout is not arbitrary. The home row runs left to right along the white keys, and the black key letters sit on the row above, in the same gapped pattern the black keys themselves follow. There is no letter between the pairs that have no black key between them, which is what makes the mapping learnable in about a minute.

Because a computer keyboard has far fewer usable keys than a piano, the mapping covers a window rather than the whole instrument, and Z and X slide that window up and down in octave steps. The current starting note is displayed between the two buttons, so a shift never leaves you guessing which octave you are in.

Clicking keys directly works across the full three octaves regardless of where the computer mapping is pointing.

What sustain actually does

Without sustain, a released key stops almost at once. That is technically correct and musically wrong for most playing, because it turns every phrase into a sequence of disconnected blips.

With sustain on, a released note fades over more than a second instead. Notes overlap, chords hold together, and a melody sounds like a melody. It is the same effect as holding down the right pedal on a real piano, and it is the single setting that most changes how the instrument feels to play.

The toggle takes effect immediately, including on notes that are already sounding, so switching it on mid phrase does what you would expect rather than waiting for the next note.

The falling hints, and what they are for

Above the keys is a lane where upcoming notes appear as bars positioned over the key they belong to. Each bar descends as its moment approaches and arrives at the keyboard exactly when the note should be played.

This is the display rhythm games use, and it works for the same reason. Reading notation requires knowing notation. Watching something fall towards the key you need to press requires nothing at all, which makes the two demo songs immediately playable by someone who has never read music.

Demo playback runs on its own audio path, completely separate from the keys you press yourself, so playing along with a demo never cuts it off or gets cut off by it.

Honest about the sound

The notes are synthesised, using a triangle wave shaped by a volume envelope rather than recordings of a real instrument. A convincing piano needs samples of every note at several playing strengths, which is tens of megabytes at minimum, and downloading that to check a chord would be a poor trade.

What you get instead is accurate pitch, immediate response and a tone that is pleasant rather than harsh. For working out a melody, checking an interval or teaching where the notes are, that is entirely sufficient. For recording something you want other people to hear, it is not.

For a guitar rather than a keyboard, Guitar Chord Finder shows fingerings, and Chord Transposer shifts a whole chord sheet into another key. To keep time while you play, Metronome is the companion.

For a single controlled frequency rather than musical notes, Tone Generator covers the full audible range, and Audio Spectrum Analyzer shows what a microphone is picking up. The rest are on the audio hub.

See it in action

Screenshot of the Virtual Piano tool with a playable keyboard starting at C4, with octave shift controls, a sustain toggle, note labels and a volume slider, and the computer-keyboard mapping shown beneath it (A S D F G H J K for the white keys, W E T Y U for the black)
Virtual Piano mid-process: a playable keyboard starting at C4, with octave shift controls, a sustain toggle, note labels and a volume slider, and the computer-keyboard mapping shown beneath it (A S D F G H J K for the white keys, W E T Y U for the black).
Diagram: where the work happens on a SysFenix page that has no file input at all: the tool arrives as ordinary JavaScript inside the page, works the answer out on your own device and renders it in place, so the upload, queue and server-side record a typical online tool needs never happen
Where the work happens on a SysFenix page that has no file input at all: the tool arrives as ordinary JavaScript inside the page, works the answer out on your own device and renders it in place, so the upload, queue and server-side record a typical online tool needs never happen.

Frequently asked questions

How big is the keyboard and what notes does it cover?

Thirty seven keys running from C3 up to C6, which is three full octaves ending on the top C. That range holds the melody of essentially anything you would want to pick out by ear, while staying narrow enough that the keys are large enough to click accurately on a laptop screen. The keyboard scrolls horizontally on a narrow display rather than shrinking the keys to unusable widths.

Which computer keys play which notes?

The home row from A through K plays the white keys in order, and W, E, T, Y and U play the black keys sitting between them, which mirrors their physical arrangement on a real keyboard. Z and X shift which octave the computer keys map onto, and the current starting note is displayed between the two buttons so you always know where you are.

What does the sustain toggle change?

How a note ends. With it off, releasing a key stops the note almost immediately. With it on, a released note rings out over more than a second instead, which is what a piano's sustain pedal does and what makes chords and phrases join up rather than sounding staccato. It applies to notes already sounding when you turn it on, not just to new ones.

What are the falling bars above the keys?

Note hints for the demo songs. Each upcoming note appears as a bar above the key it belongs to and descends as its moment approaches, reaching the keyboard exactly when it should be played. It is the same visual idea rhythm games use, and it makes a melody followable without reading notation.

Which demo songs are included?

Two, Twinkle Twinkle Little Star and the Ode to Joy theme, each with its own tempo. They are there to demonstrate the falling hint display and to give the keyboard something to do on first load rather than as a music library. A demo plays through its own audio path, entirely separate from your own key presses, so you can play along over the top without either interfering with the other.

Does it sound like a real piano?

No, and it is worth being straightforward about that. The sound is a synthesised triangle wave with a volume envelope, not a recorded piano. A convincing piano sound needs sampled recordings of every note at several volumes, which would be a large download. What you get is clean, in tune and responsive, which is what matters for picking out a melody or checking a chord.

Is anything recorded or uploaded?

No. Every note is generated live in your browser and sent straight to your speakers, so there is nothing to record and nothing to send. There is no way to save what you played, which is a real limitation rather than an oversight, and the page never asks for microphone access because it only produces sound.

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