Play Mini Synth Online — Free Pocket Subtractive Synth
Tweak a pocket synth in your browser: four waveforms, resonant filter cutoff, two octaves, keyboard and MIDI — no download.
Bottom row plays C4–B4, top row C5–B5 — twist the cutoff while you play. Keys Z–M and Q–U.
How to Play in Four Steps
- Play the two-octave keys — bottom row C4–B4, top row C5–B5 — with glissando slides.
- Flip the waveform: saw for bite, square for hollow, triangle for soft, sine for pure.
- Ride the cutoff knob while holding notes to sweep the filter open and closed.
- Shift octaves or connect MIDI for bass lines and leads, then record your take.
A Short History of the Synthesizer
Robert Moog modular synths of 1964 let musicians sculpt sound from raw waveforms and filters. Wendy Carlos 1968 album Switched-On Bach proved synths could play anything, and Kraftwerk made them the sound of the future.
From 80s pop to techno, film scores and bedroom beats, the subtractive synth — oscillators into a filter — remains the core of electronic music worldwide. Shape those sounds yourself on the free web audio synthesizer above.
Acoustically there is no box at all — raw oscillator waveforms sculpted by a resonant lowpass filter, reproduced live with four switchable waves and a sweepable cutoff.
Synth Quiz
0 / 3 · Score
Which module shapes a synth note by removing harmonics?
Which waveform sounds the brightest and buzziest?
Which album proved synthesizers in 1968?
Frequently Asked Questions
Play the on-screen keys, use Z–M for the lower octave and Q–U for the upper, or connect a MIDI keyboard. Waveform and cutoff shape every note live.
It opens and closes the lowpass filter: low values sound dark and mellow, high values bright and buzzy. Sweep it while holding a note for classic filter sweeps.
The cutoff opens and closes the lowpass filter on this virtual analog synth: low values sound dark and round, high values bright and buzzy — sweep it live while holding notes.
Four: sawtooth for biting leads, square for hollow bass, triangle for soft flutes and sine for pure sub tones — switch them mid-note on this waveform synthesizer.
Yes — two labeled octaves, touch support on phones and tablets, and optional MIDI make it a simple online synth for beginners that still teaches real subtractive synthesis.
No. Everything runs in the browser with the Web Audio API — no samples, no plugins, no account.