A gesture synth — also searched as hand gesture synth — is an instrument you play with hand movements instead of keys: a camera reads your hands, software turns motion into sound. Gesture Synth Weld is a free one that runs entirely in your browser: webcam on, hands up, music out.
A gesture synth — a hand gesture synth in full — replaces the keyboard with movement. Instead of pressing keys, you move your hands in the air: a sensor — a webcam, a depth camera, or a sensor glove — reads the position of your hands and fingers, and software maps that motion onto musical parameters like pitch, volume and tone. Raise a hand, the volume rises. Spread your fingers, the chord opens up.
Gesture Synth Weld is a browser-based gesture synth with a fixed two-hand division: your left hand picks the harmony (finger count selects scale degrees I–VII, wrist tilt picks major or minor) while your right hand shapes the expression (height is volume, tilt is tone, finger count sets chord thickness). Nothing to install, nothing to buy — if your device has a camera, you already own the instrument above. The full gesture tutorial maps every move.
The same two words mean different things to different people. Pick your path — all three are answered on this page:
You want music in seconds, in a browser tab. That's the instrument above — one click starts it.
Sensor gloves, Arduino kits, Leap Motion rigs — real, but soldering, drivers and €100+ in parts. The zero-solder route is the instrument above.
A gesture synth turns body movement into sound. Browser-based gesture synths use your webcam to track your hands — no hardware controller needed. Gesture Synth Weld pushes the format further: each finger becomes a musical command, your left hand picks harmony while your right hand shapes expression, and everything runs live in the browser with zero installs.
Compare that to hardware gesture synths (gloves, ring sensors, MIDI theremins): they're powerful, but they cost hundreds of dollars and need setup. A webcam gesture synth gets you the same experience for free — as long as your hands are in the frame. That's the trade-off: no hardware cost, just your two hands.
Three ways to play music with gestures — here's how they compare:
| Approach | Cost | Setup | Pros | Cons |
|---|---|---|---|---|
| Browser gesture synth (webcam + hand tracking) | Free | None — open the page, allow camera | Zero install, zero cost, runs on any device | Needs light and clear hand visibility |
| Hardware gesture synth (gloves, ring sensors, MIDI theremins) | $100 – $1,000+ | Drivers, calibration, MIDI wiring | Precise, low latency, works in any light | Expensive, bulky, needs setup |
| DAW + MIDI controller | Software + hardware cost | Install DAW, configure mappings | Full production power, unlimited tracks | Steep learning curve, desk-bound, not gesture-based |
Bottom line: hardware wins on raw precision; the browser wins on everything else — zero cost, zero setup, record and share from the same tab. That's why this page exists: press play and try the free one first →
Prefer an instrument you can pick up in seconds? See the step-by-step tutorial — or just press play below and start with the instrument above.
Press play above, grant camera permission. Tracking runs on your device — video is never uploaded.
Choose a key (C–B, default A). 1–5 fingers select scale degrees I–V. Index+Pinky = VI, +Thumb = VII. Default mode is locked to Major — switch to Scale+Tilt in settings to control major/minor with wrist tilt.
Fingers set chord complexity (1=triad, 2=inversion, 3=7th, 4=9th). Height = volume, tilt = tone. Both hands required for sound — left fist mutes it, right fist restores octave. Full map: gesture tutorial →
Up to 120 seconds per take — audio, full video, or skeleton animation — then download or share.
Searching for a gesture synth app for Android or iPhone? There is deliberately no app to install — no App Store download, no storage space, no updates, no account. The URL is the app: open this page on any phone, tablet or laptop, allow the camera, and you're playing the instrument above in seconds.
A download would only add friction — the full instrument already runs in the browser on Android and iOS alike, and a link is all it takes to share it with a friend. Prefer a home-screen icon? Use your browser's "Add to Home Screen" — it opens this same page, always up to date.
A gesture synth is a musical instrument played with hand or body gestures instead of keys: a sensor reads your movements and software turns them into sound. Gesture Synth Weld is a free browser-based gesture synth — the instrument at the top of this page. Webcam on, hands up, music out.
This page is the online version — no app to install. Play in the browser above: allow the camera and you're playing. That's the whole point of a browser-based hand gesture synth: the URL is the app. Full answer: why there's no app →
No. All you need is a computer or laptop with a built-in or USB webcam, and a modern browser like Chrome, Edge, or Firefox. No MIDI controllers, no external sensors, no downloads. Your webcam handles all the input — MediaPipe's hand tracking model runs entirely on your device.
Gesture Synth Weld works in any modern browser that supports the Web Audio API and getUserMedia — including Chrome 90+, Firefox 90+, Edge 90+, and Safari 15+. For the best hand tracking experience, Chrome or Edge is recommended since they support MediaPipe's WebGL2 backend most efficiently.
Yes! Click the Record button to start capturing your performance (up to 120 seconds). A 3-2-1 countdown gets you ready, and a 3-2-1 wrap-up warns you before the recording stops. Choose what to capture: audio only, full video (camera with neon skeleton), or skeleton animation (no camera feed — privacy-friendly). Pick an aspect ratio for your sharing platform: 9:16 for TikTok/Reels/Shorts, 16:9 for YouTube, 1:1 for Instagram. Sing along? Your microphone is mixed into the recording (toggleable) — perfect for singing over your own chords. Pick your microphone in the chooser if needed (some Macs default to a virtual device that records silence), and balance voice vs chords with the recording-mix slider — headphones give the cleanest mix. After recording, download the file — or on mobile, share it straight to your apps from the share sheet (the share message carries our brand and gesturesynthweld.com). Your camera feed is never uploaded to any server.
Gesture Synth Weld supports all 12 keys (C through B) with two right-hand modes. In Finger Layout mode: 1 finger = triad, 2 fingers = 1st inversion, 3 fingers = 7th chord, 4 fingers = 9th chord. In Fixed Chord mode, choose from 8 chord types: Major Triad, Major 1st Inversion, Minor Triad, Diminished, Sus2, Sus4, Major 7th, and Dominant 7th. Lock to a fixed major or minor mode, or enable Scale+Tilt in settings to switch between major and minor with left-hand wrist tilt. See the full gesture table →
Yes — Keyboard Mode turns your physical keyboard into the instrument (desktop only, no camera permission and no model download needed). Enable it in Settings → "No camera? Keyboard mode" or with the ⌨ Keyboard button in the top toolbar (in keyboard mode it becomes 📷 Camera — one click switches back to hand gestures), then press 1-7 for scale degrees I-VII (hold to play, release to stop), [ / ] for minor/major, 8/9/0/- for chord styles, Shift for octave down, ↑/↓ for volume and ←/→ for the filter sweep, and Space to stop. A real-keyboard guide with a demo animation shows you every key the first time — replayable anytime from the ? help panel. Recording in keyboard mode captures audio (add your voice with the mic) — video modes need a camera feed, so they're hidden there.
Gesture Synth Weld features a unique two-hand division system: your left hand controls harmony (key selection, scale degree, major/minor toggle) while your right hand controls expression (chord complexity, volume, tone, octave). Unlike basic gesture synths, it includes an arpeggiator for harp-like sweeps, an auto bass generator for low-end foundation, a sawtooth synth engine with real-time filter sweep, support for 9th chords (4-finger), 8 fixed chord styles, and built-in MP4/M4A recording. It's also open source under the MIT license.
Yes! Gesture Synth Weld is free to use. We support the development and hosting of this tool through non-intrusive advertising. No registration, no sign-up, no paywall — just open and play. The source code is also available on GitHub under the MIT license for anyone who wants to study, modify, or contribute.
Gesture Synth Weld is one specific gesture synth: a two-hand browser instrument — left hand harmony, right hand expression — with recording built in. "Gesture synth" is the generic category, and it includes hardware gloves, DIY kits and DAW plugins too. If you searched the generic term, this page is the free browser member of that family — press play above and try it.
Yes — this site is MIT-licensed open source on GitHub. The stack is MediaPipe hand tracking plus a Tone.js synth, all running locally in the browser.
Theory over — your hands already know what to do.