ModularSynth — a free modular synthesizer in your browser

Put modules in a rack, patch them with cables and build your own sounds and tracks, right in your web browser. No install, no account, no cookies: everything stays on your device. Works on computers, tablets and phones, in English and in French.

What you can do

• Patch 38 modules: oscillators, filters, envelopes, LFOs, sequencers, effects, a sampler and an audio input.
• Play with your computer keyboard, an on-screen keyboard or a MIDI keyboard, with up to 16 voices of polyphony.
• Make loops with the Step Seq, the Trigger Seq drum machine and the Note Grid piano roll (the last two with four pattern pages).
• Map any knob to your MIDI controller with MIDI learn, and sync the Clock to Ableton Live or any DAW over MIDI clock.
• Save scenes, chain them into a song, record a WAV, and share a patch with a link.
• Start from 27 ready-made presets: pluck bass, polyphonic pad, acid techno, FM bell, West Coast lead, generative ambient…

Learn modular synthesis by ear

The Learn course guides you through five chapters and 23 short exercises: from signal to sound, understanding by playing (voltage, modulation, envelopes, scales, waveforms), a machine that plays by itself, your first track, and a gritty techno loop. Every step tells you what you are about to hear, so you understand what each knob and cable does.

Modules

• Sources: VCO, VCO 2 (hard sync, linear FM), Wavetable, Noise, Sampler, Audio input.
• Filters and dynamics: VCF, Ladder (24 dB/oct), VCA, Mixer, Stereo Mix, Quant, Compressor (sidechain), EQ.
• Control: MIDI→CV, ADSR, LFO, Clock, Step Seq, Trigger Seq, Note Grid, S&H, Slew, Attenuverter, Comparator, Logic, Pad XY.
• Effects: Delay, Reverb, Chorus, Distortion, Wavefolder, Phaser, Ring Mod.
• Space: Spatial (direction, height and distance in stereo, headphones or 5.1/7.1 surround).
• Tools: Scope, Output, Memo.

FAQ

Is ModularSynth free?

Yes. ModularSynth is free, with no account and no ads.

Do I need to install anything?

No. It runs in a modern web browser on a computer, a tablet or a phone.

Can I play it with a MIDI keyboard?

Yes. Plug in a MIDI keyboard to play notes, map knobs with MIDI learn, or use your computer keyboard.

Can I use it with Ableton Live or another DAW?

Yes. Send MIDI from your DAW to the browser (loopMIDI on Windows, IAC bus on Mac); the Clock module can follow the DAW's MIDI clock. Record the sound with a virtual audio output or export a WAV.

I'm a beginner: can I learn modular synthesis with it?

Yes. The Learn course guides you in five chapters, from your first sound to a full track; every step tells you what you are about to hear.

Are my patches private?

Yes. Patches and sounds stay in your browser; nothing is sent to a server.