Webcam Theremin Online
Move your hands in the air and play a gliding note. Free, right in your browser.
Play a theremin with your webcam: move your right hand for pitch, raise your left hand for volume. Or drag on the pad. Your video stays on your device.
This is a theremin online that you play with your webcam. Your right hand slides left and right to change the pitch, and your left hand rises and falls to set the volume. You never touch anything, which is exactly how the real instrument works.
Press Start Playing, allow the camera, and move your hand slowly across the picture. No install, no account, and the video stays on your device. If you have no camera, a touch pad lets you play with a finger or mouse instead.
What Is a Theremin?
A theremin is an electronic instrument you play without touching it. It was invented by the Russian physicist Léon Theremin around 1920. The player moves one hand near an antenna to control pitch and the other near a second antenna to control volume, which gives the theremin its eerie, singing glide.
A real theremin senses your hands through electric fields. This virtual theremin uses your webcam instead: Google's MediaPipe hand model runs inside your browser, finds your hands in the picture, and turns their position into pitch and volume. The idea is the same, and you can try it without buying any gear.
How the Webcam Theremin Maps Your Hands
Hands are assigned by where they appear on screen, and the view is mirrored so it feels like playing in front of a mirror.
| Hand | Movement | Controls |
|---|---|---|
| Move left ↔ right | Pitch, across three octaves from the key note | |
| Raise or lower | Volume | |
| Only one hand in view | That hand sets pitch; volume stays at a default level | |
| Take your pitch hand away | The note fades out |
Pitch, Volume and One-Hand Play
Pitch range
The pitch hand covers three octaves from left to right, starting on the note of the current key. In C, the far left is C3 and the far right is C6. Change the key in the controls to move the whole range.
Volume
Raise your volume hand to get louder and lower it to fade out. Remove the pitch hand from view and the note fades away, so you can phrase notes the way a theremin player does.
Playing with one hand
If only one hand is in view, that hand controls pitch and the volume stays at a steady default level. This is a handy way to start, since you only have to think about one thing.
How to Play the Online Theremin
Five steps from a silent page to your first melody.
- 1
Open Theremin mode
Use this page or pick the Theremin tab on the home page. Press Start Playing and allow the camera when your browser asks.
- 2
Find your space
Sit about an arm's length from the camera in good light, with room to move your hand across the whole picture.
- 3
Slide your right hand for pitch
Move it slowly from left to right and listen to the note rise. Start with Snap to scale on so every position lands on a clean note.
- 4
Raise your left hand for volume
Lift it to swell the note and lower it to fade. Try a slow swell on a single held note first.
- 5
Shape the sound
Switch between sine and triangle waves, and turn vibrato on for a wavering, classic theremin tone.
Theremin Sound Options
Snap to scale or continuous glide
With Snap to scale on, the pitch locks to the notes of the current key. Anywhere you hold your hand, you hear an in-key note, which makes melodies much easier for beginners.
Turn it off for a continuous glide. Now every tiny movement bends the pitch, just like a real theremin. It is harder to stay in tune, but you get the sweeping slides the instrument is famous for.
Vibrato on or off
Vibrato adds a gentle wobble to the pitch. Keep it on for a singing, old-movie sound, or turn it off for a pure, steady note that is easier to tune by ear.
Sine or triangle wave
The sine wave is smooth and pure, close to the classic theremin voice. The triangle wave has a little more bite, so it stands out more in a clip or a noisy room.
No Camera? Use the Touch Pad
If the camera is blocked or missing, Theremin mode shows a touch pad. Press and drag on it with a finger or mouse: left and right change the pitch, up and down change the volume.
The same Snap to scale, vibrato and wave options apply, so the touch pad is a quick way to try ideas on a phone or a computer without a webcam.
Practice Ideas for Your Virtual Theremin
A few short exercises build control fast. Start with Snap to scale on, then try them again with it off.
- Play the scale slowly from the lowest note to the highest and back. Pause on each note for a second.
- Hold a single note and swell the volume up and down without letting the pitch drift.
- Jump between two notes a few steps apart, then try wider leaps across the range.
- Play simple melodies you know by ear, such as a nursery tune, and find each note by listening.
- Turn Snap to scale off and slide slowly between two notes so the glide sounds smooth, not shaky.
- Pick a minor key and improvise a slow, spooky line with vibrato on.
Tips for Steady Pitch
The camera can only follow what it sees clearly. These habits make the pitch hand easier to track and easier to control.
- Light your hands from the front. A bright window behind you turns your hands into dark shapes.
- Stand in front of a plain background so the hand model does not mix you up with the room.
- Keep your palm open and facing the camera while you slide. A loose, relaxed hand moves more smoothly than a stiff one.
- Move from your elbow, not your wrist. Big, slow movements give you finer control over pitch.
- Use desktop Chrome or Edge for the smoothest frame rate. Safari is supported too.
- If the note wobbles when you hold still, rest your elbow on the desk or turn on Snap to scale so small movements stay on one note.
Keep Playing
Play chords with your hands
Go back to the chord mode on the home page and play full chords with finger signs.
Record your theremin
Save a short vertical or wide clip with sound. See the recording guide for tips.
Learn the chord hand signs
The hand sign tutorial explains every chord sign and voicing.
Learn a song
Try the song list with chords shown step by step in chord mode.
Online Theremin FAQ
Can I really play a theremin online for free?
Yes. Theremin mode is free in your browser. There is nothing to install and no account to create.
Which hand controls pitch?
Your right hand controls pitch by moving left and right. Your left hand controls volume by moving up and down. With only one hand in view, that hand sets the pitch.
What range does it cover?
Three octaves, starting on the note of the current key. In C that is C3 to C6. Change the key to shift the range.
Why does my note sound out of tune?
With Snap to scale off, the pitch follows every small movement, just like a real theremin. Turn Snap to scale on to lock each position to a note of the key.
Is my webcam video uploaded?
No. Hand tracking runs on your device and the video never leaves your browser.
Can I play without a webcam?
Yes. Use the touch pad: press and drag, with left and right for pitch and up and down for volume.
Does it work on a phone?
Yes, but tracking is smoother on a computer. On a phone, turn it sideways so your hands have room, or use the touch pad.
Can I record my theremin playing?
Yes. Press Record to save a clip of up to 60 seconds with sound, in 9:16 or 16:9. The recording guide covers the details.
Do I need to read music to play?
No. Turn on Snap to scale and every hand position lands on a note of the key, so you can find melodies by ear and simply listen for what sounds right.
How is this different from a real theremin?
A real theremin senses your hands with antennas and electric fields. This webcam version reads your hand position from the camera picture, and it offers extras such as Snap to scale.