A full subtractive synthesizer in your browser — 28 presets, a 16-step sequencer, arpeggiator, FX rack, 40+ skins, and one-click video export. No download or signup.
A synthesizer (“synth”) makes sound electronically instead of recording a real instrument. This one is a subtractive synth: it starts with a bright, buzzy tone, then you subtract and shape parts of it with filters and envelopes until it sounds the way you want — a fat bass, a soft pad, a sharp lead, and so on.
The sound flows left → right: the Oscillators make the raw tone, the Filter removes frequencies, the Envelopes and LFO add movement, and the FX rack adds polish. You don’t need to understand all of it — pick a preset and turn knobs. Nothing can break.
Everything on the panel is one of three things. Once you can tell them apart, the whole synth makes sense:
The sound source. Each oscillator makes a waveform, and its shape sets the basic character:
Using two oscillators and slightly detuning one from the other makes a thick, wide sound. Octave and Semi shift a layer’s pitch up or down.
The filter removes part of the sound to make it brighter or darker.
Try this: hold a note and slowly turn Cutoff down then up — that sweep from muffled to bright is the single most useful move on a synth. Add a touch of Resonance for that “wah” squelch.
Adds a layer of hiss (like radio static) mixed in with the oscillators. A little adds breath and grit; a lot is useful for wind, percussion, or risers.
An envelope describes how something changes over the life of a note. AMP ENV shapes the volume; FILT ENV shapes the filter brightness. Both use four stages (ADSR):
You’ll hear it when: you play a note. Short Attack + short Release = a tight, plucky stab; slow Attack + long Release = a soft pad that fades in and lingers. If notes cut off abruptly, raise Release; if a sound feels too slow to speak, lower Attack.
An invisible, slow wave that wobbles something automatically. Point it at pitch for vibrato, at the filter for a wah/wobble, or at volume for tremolo. Rate = how fast it wobbles, Depth = how much.
Nothing happening? The LFO does nothing while Depth is at zero — turn Depth up to hear it. Pick the destination (pitch / filter / amp) first, then raise Depth, then set Rate to taste. Great for dubstep wobble bass: point it at the filter, medium depth, slow-ish rate.
The arpeggiator takes a chord (several keys held at once) and plays the notes one at a time in a repeating pattern, locked to the tempo — that bubbly, rhythmic “dance/trance” effect.
You must turn it on first. Click the ON button in the ARP module so it lights up — until then the arp does nothing. Then hold down two or more keys and you’ll hear them ripple instead of sounding together.
You’ll hear it when: the arp is ON and you’re holding more than one note. One note alone just repeats that single note.
How to use: these knobs start at zero (no effect) — turn one up to dial the effect in. A little goes a long way: try a small amount of Reverb and Chorus on almost any sound to make it feel finished, and Delay on leads for an echoing, spacious feel.
A 16-step grid that plays a repeating riff. Click a step to turn it on; drag or scroll on a step to set its pitch; shift-click for an accent. Press ▶ PLAY to start, CLR to clear, RND for a random pattern.
Type letters to play a melody — each letter triggers its note, a space is a pause, and [abc] plays a chord. Ctrl+Enter plays, Esc stops, DEMO loads an example, LOOP repeats it.
In the sequencer bar, click the 🎹 SYNTH / 🥁 BEATS toggle to turn the step grid into a drum machine. Each row is a drum (Kick, Snare, Clap, Hats, Tom) and each column is a step in time, read left to right.
You don’t need a real piano — your typing keys are the keyboard:
Your choice is saved + included in any share link you copy with 🔗
ButtonBass is a free online music creation platform where anyone can make beats, play instruments, and explore electronic music — all inside a web browser with no downloads or sign-ups required. Since its launch, ButtonBass has been used by millions of musicians, students, and educators around the world to learn about music production, experiment with sound design, and have fun making music.
The site features dozens of interactive instruments and games, including virtual pianos, synthesizers, loop-based cube mixers, rhythm games, and collaborative jam rooms. Every tool runs on the Web Audio API, delivering real-time audio synthesis and low-latency playback on desktop, tablet, and mobile devices.
The ButtonBass Synth is a full subtractive synthesizer that runs entirely in your browser using the Web Audio API. Two oscillators feed a state-variable filter, two ADSR envelopes shape amplitude and filter movement, an LFO modulates pitch, filter or amp, and a multi-stage FX rack handles drive, bit-crush, phaser, chorus, delay, and reverb. A poly/mono/unison voice mode and a built-in arpeggiator round out the engine.
Play it with your QWERTY keyboard — the bottom two rows act as a 2-octave piano (Z, X, C… for white keys; S, D, G, H, J for black). The OCT − / OCT + buttons shift the playable range, and any plugged-in MIDI controller is auto-detected. The display shows the current patch and the last note played, and a live oscilloscope is built into the screen.
Choose any of the 28 built-in presets from the dropdown — leads, basses, pads, plucks, lo-fi keys, 8-bit, acid, bells, brass, vocal choirs, FM e-pianos, trance gates, dub wobbles, growls, metal leads, alien sirens, cathedrals, sci-fi sweeps and more. Hit SAVE to store a tweak as your own patch. Click the dice (⚂) for a fully random patch, or hit JAM to roll a curated vibe — Acid House, Lo-Fi Lounge, Synthwave Cruise, Trance Lift, Cinematic Drift, Trap Bounce, or Dream Pluck — that locks tempo, scale, rhythm, preset family, and arp settings together so it sounds intentional. Click JAM again to stop.
The 16-step sequencer lets you toggle steps on/off, drag or scroll on a step to set its pitch, and shift-click for accents. BPM, swing, and gate length are right next to the transport. The Song Script textbox below it plays a typed string of letters as melody: each letter triggers its mapped note, a space adds a pause, and [abc] plays a chord. Press Ctrl+Enter to play, Esc to stop, hit DEMO for the built-in song, or LOOP for endless playback.
Hit the SKINS button to browse 40+ visual themes — vintage cream, midnight, cyberpunk, vaporwave, matrix, gold, carbon, and dozens of parody “silly-product” skins. Each skin can change not just the colors, but the knob shapes, button styles, fonts, and even the keyboard layout. Hit Surprise Me to roll a random one, or Party Mode to auto-cycle every 2 seconds.
Hit REC to capture audio as a WAV file. Hit VID to render a vertical 9:16 video with the live visualizer baked in — ready to upload to TikTok, Instagram Reels, or YouTube Shorts. The 🔗 button copies a share link that loads your current patch, song, and skin so friends can hear exactly what you made.
Beyond the Synth, ButtonBass offers a growing library of browser-based music instruments and games. Explore loop-based cube mixers for dubstep, house, techno, electro, reggaeton, and 8-bit genres. Play virtual pianos in every style — 8-bit, trap, ATL, dubstep, drum, jungle. Try rhythm games like Beat Slicer, Piano Drop, Piano Tile Tap, and the Memory Piano. Every tool is free, works on any device, and requires nothing more than a modern web browser.
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