THE THREE FAST ANSWERS
No sound? Check your phone Silent Mode switch. The app itself warns about this before you start, and most people dismiss the warning without reading it.
Stuck on "waiting for your hands"? The camera permission was blocked or the browser tab lost it. Nothing happens until it sees a hand.
Which site is real? The original is the Vercel app credited to Eric Wei. At least nine other domains now serve a version of it under near-identical names.
Is it safe? Honest answer below - there are things we can confirm and one thing nobody publishes.
No sound: the Silent Mode trap
This is the most common failure and it is not a bug in the app.
Before Gesture Synth starts, it shows a short note asking you to check Silent Mode and your volume, with a "Got it!" button. Almost everyone taps "Got it!" without reading it, then plays with their hands in front of the camera, sees the interface responding, and hears nothing.
Work through these in order:
- iPhone: the physical mute switch on the left edge, or the bell icon in Control Centre. Safari respects it for web audio even when your media volume is up.
- Android: media volume is separate from ringer volume. Press volume up while a sound should be playing, then check the media slider specifically.
- Desktop: check the per-tab mute. Right-click the browser tab and look for "Unmute site" - a previously muted tab stays muted.
- Still nothing: tap or click anywhere on the page once. Browsers block audio until the page has received a direct interaction, and if your first contact with the page was a gesture in front of the camera rather than a tap, audio was never unlocked.
That last one catches people who open the app, hold their hands up immediately, and never actually touch the screen.
Camera will not start, or it says "waiting for your hands"
The app states plainly that camera access is required to play. There is no keyboard or mouse fallback - no camera, no instrument.
"Waiting for your hands..." is the normal idle state, not an error. It means the camera is live and the app has not yet detected a hand. If it never changes:
- Permission was denied once and remembered. Tap the padlock or camera icon in the address bar and set camera to Allow, then reload. Browsers do not re-prompt after a denial.
- Another app holds the camera. Zoom, Meet, Teams, Photo Booth, or another browser tab. Only one can use it at a time on most systems. Close them and reload.
- You are on HTTP, or in an in-app browser. Camera access requires a secure context. Links opened inside Instagram, TikTok or Messenger often run in a restricted in-app browser - tap the menu and choose Open in Safari or Open in Chrome.
- Lighting and framing. Hand tracking needs your hand clearly separated from the background. A backlit window behind you is the usual culprit. Face a light source, not away from one.
- Hands too close. The app wants to see the whole hand including the wrist. Pull back about an arm length.
Is Gesture Synth safe?
Here is the honest version, separated into what can be confirmed and what cannot.
What the app asks for: camera only. It does not request microphone access. The permission prompt you get is the browser's standard one, and you can revoke it from the address bar at any time.
What there is no account for: no sign-up, no email, no payment step. You open a URL and play.
What nobody publishes: the original app does not state where the video from your camera is processed. Browser hand-tracking of this kind normally runs entirely inside your own browser, with no frames leaving the device - but normally is not the same as documented, and the app carries no privacy statement saying so. We are not going to tell you it is private when the only thing we can actually verify is that it asks for camera access.
The part that should make you careful: search for Gesture Synth privacy information and the results fill with copies of the site rather than the original. Those copies set their own terms, their own analytics and their own scripts. A privacy promise on a page that is itself a copy of someone else's project is worth exactly what you paid for it.
Practical answer: the risk of granting camera access to a browser tab for a few minutes is low, and you can revoke it in two taps afterwards. Do it on the original URL rather than a lookalike, and close the tab when you finish, which releases the camera.
Which Gesture Synth is the real one
This is why "gesture synth weld" is one of the most searched variants: people are trying to find the actual address and getting a page of near-identical domains instead.
The original is hosted on Vercel at gesture-synth-weld.vercel.app. The in-app guide credits Eric Wei as its creator and links to his site, and the footer credits the Instagram handle @indecisive.eric. The "weld" in the URL is a Vercel deployment suffix, not part of the name - which is why so many people search for it as though it were a product called Gesture Synth Weld.
Domains currently serving a version of the project under similar names include gesturesynth.org, gesturesynth.net, gesturesynth.me, gesturesynth.co, gesturesynth.cc, gesturesynth.fun, gesture-synth.com, gesturesynthweld.com and gesture-synth-weld.net. We are naming them as plain text rather than linking them. Several rank above the original.
We are not accusing any specific domain of anything beyond being a different site from the one Eric Wei built. But if you are deciding where to point a camera, the distinction matters, and the original is the one credited to its author.
How Gesture Synth actually works: the full control map
The queries asking how it works and asking for a tutorial get answered badly everywhere, because most pages describing it have not opened it. This is the complete control scheme as the app documents it.
Modes: Two-Handed, or Left Hand Only.
Left hand - what chord
| Gesture | Result |
|---|
| Tilt inward | Major |
| Tilt outward | Minor |
| 1 to 5 fingers | Scale degrees I to V |
| Index + pinky | VI |
| Index + pinky + thumb | VII |
| Hand in top half | Pitch shift up one semitone |
| Hand in middle | Normal pitch |
| Hand in bottom fifth | Pitch shift down one semitone |
Pitch shift has to be enabled first - there are separate Raise and Lower toggles, and until one is on, vertical position does nothing.
Right hand - how it sounds
| Gesture | Result |
|---|
| Finger count | Chord quality: root position, 1st inversion, major/minor 7th, dominant/diminished 7th |
| Thumb tucked in | Octave up |
| Thumb out | Octave down |
| Tilt inward | More filter |
| Tilt outward | Less filter |
| Hand higher | Louder |
| Hand lower | Softer |
Settings
A key selector covering A through G#, and a set of sounds: Warm, Bright, Retro Synth, Strings and Horns. Volume and Filter show as Fixed in the settings panel because they are controlled by your right hand position rather than by a slider.
The practical takeaway: your left hand chooses the chord, your right hand shapes it. If it sounds like random noise, you are almost certainly moving both hands at once. Hold the right hand still and play chords with the left until the mapping clicks, then start shaping.
Is it free, and is it AI?
Free: yes, on the original. There is no payment step, no account and no trial limit. It is a personal project published on a free Vercel deployment.
AI: depends which definition you are using, and this is worth being precise about because the answer is routinely overstated. The hand tracking is machine learning - a computer vision model locating the joints of your hand in the camera feed, many times a second. That is the AI part, and it is the same class of model that powers hand tracking in video calls.
What it is not: there is no language model, nothing generative, and no AI composing music. The mapping from your fingers to a chord is a fixed rule set written by a human, exactly as documented in the tables above. Five fingers always means degree V. The instrument does not make musical decisions - you do.
That distinction matters if you came here from a page claiming the AI writes the music. It does not.
Who made it
Eric Wei, credited inside the app's own guide, which links to his personal site, with @indecisive.eric credited in the footer. It is a personal project rather than a company product, which explains several things at once: no privacy policy, no support channel, no pricing page, and a URL that still carries its deployment suffix.
It also explains the clone problem. A solo project with no legal team and a viral moment is the easiest thing in the world to copy, and the copies have the budget to outrank the original.
FAQ
Why can I not hear anything on Gesture Synth?
In order of likelihood: phone Silent Mode is on, the browser tab is muted, media volume is separate from ringer volume on Android, or you never tapped the page. Browsers refuse to play audio until the page has had a direct tap or click, and waving at the camera does not count as one.
Does Gesture Synth record me?
There is no record button and no upload step in the app. What it does not do is publish a statement about where the camera feed is processed. Browser hand tracking of this type usually runs locally, but the app does not document it, so we are not stating it as fact. Revoke the camera permission from the address bar when you are done if it concerns you.
What is gesture synth weld?
Not a product. "weld" is the random suffix Vercel added to the deployment URL when the project was published. The app is called Gesture Synth; the full address just happens to contain the word, which is why thousands of people search for it as a name.
Does Gesture Synth work on a phone?
Yes, in a mobile browser with camera access. The main problems on phones are Silent Mode killing the audio, and in-app browsers inside Instagram or TikTok blocking the camera. Open it in Safari or Chrome directly rather than tapping a link inside a social app.
Do I need a microphone?
No. It asks for camera only. If something asks you for microphone access while claiming to be Gesture Synth, you are not on the original app.
Why does it keep saying "waiting for your hands"?
That is the idle state while the camera is on but no hand is detected. Move back about an arm length so your whole hand and wrist are in frame, face a light source instead of having one behind you, and make sure no other app is holding the camera.