Online Keyboard Synth

Online Keyboard Synth is a free browser synthesizer. Press Z, X and C to start, or tap the on-screen piano on a phone, and use Lower and Higher to change octave; a compatible MIDI controller works too. There are ten presets, including Retro Lead, Warm Pad, Deep Bass, Super Saw, Bell and Electric Piano, plus a random option. A sound design panel exposes the waveform (sine, triangle, square or saw), filter cutoff and resonance, an ADSR envelope, reverb and delay, and you can save your own sounds in the browser. Five short lessons walk through oscillators, filters, envelopes, reverb and detune while the synth responds. A recorder captures what you play for download. Everything runs locally with no account, and the about page says it is a focused instrument rather than a full DAW, with no cloud projects or automatic backup.