WAVR PLUGIN · OPEN SOURCE · v3.0.0

DRUM
/MACHINE
WAVR PRO

A 16/32-step sequencer that runs entirely in your browser. 8 synthesized instruments, per-row timing divisions from 1/32 to 1/4T, a 18-sound offline sample library, and file upload. Zero dependencies. Zero install.

▶ Launch demo ↓ GitHub ← Back to SDK

WEB AUDIO API 8 INSTRUMENTS PER-ROW TIMING 18 SYNTH SAMPLES FILE UPLOAD WORKS OFFLINE

WHAT IT DOES

Every feature.
No server.

Everything runs in your browser via the Web Audio API. Your audio never leaves your machine.

⬡

Step grid

Toggle steps with a click. Right-click any step to set its velocity (0–100). Group markers every 4 steps. Flash animation on active step.CORE

◉

8 Instruments

Kick, Snare, Clap, HH Closed, HH Open, Tom Hi, Tom Mid, Ride. Each synthesized with Web Audio nodes — no sample files required for the defaults.SYNTHESIS

Per-row timing

Each row has its own step division: 1/32, 1/16, 1/16T, 1/8, 1/8T, 1/4, 1/4T. Rows run fully independent clocks — like Maschine's note repeat.POLYRHYTHM

≈

Swing

Global swing 0–75% applied to all rows proportionally. Even steps fire on-grid; odd steps are pushed forward. Affects live playback and offline bounce equally.FEEL

◈

Sample slots

Every row has a sample slot. Load from the built-in library, drag a file from your desktop, or upload via the browser panel. Synth fallback is instant if slot is empty.SAMPLER

●

18 built-in sounds

Rendered locally via OfflineAudioContext — no network required. 808 Kick, Crack Snare, Sizzle Hat, FM Bell, Crash, and more.OFFLINE

↓

Offline bounce

Render a full-quality 1-bar loop to AudioBuffer via OfflineAudioContext. Per-row timing, samples, and swing all applied correctly in the bounce.EXPORT

⊞

Genre presets

Hip Hop (90 BPM, 30% swing), House (128 BPM), Techno (138 BPM), Jungle (170 BPM). Each loads a full 32-step pattern and resets BPM.PRESETS

PER-ROW TIMING

Polyrhythm
out of the box.

Every row runs its own independent clock. Set hi-hats to 1/32 for double-time, kick to 1/4 for a sparse groove, ride to 1/8T for a triplet feel — all in the same pattern.

1/32

Thirty-second note

Twice the density of default — double-time hi-hat rolls, ghost notes

0.5× base duration

1/16

Sixteenth note — default

The standard grid. 16 steps = 1 bar at any BPM

1× base duration

1/16T

Sixteenth triplet

3 steps fit where 2 would — shuffle feel on any row

2/3× base duration

1/8

Eighth note

Half as many hits per bar — sparse, spacious patterns

2× base duration

1/8T

Eighth triplet

3 in the space of 2 eighth notes — rolling tom fills

4/3× base duration

1/4

Quarter note

One hit per beat — four-on-the-floor kick, whole-bar accents

4× base duration

1/4T

Quarter triplet

3 beats in the space of 2 — maximum cross-rhythm tension

8/3× base duration

VISUAL — 1 BAR, 4 ROWS, DIFFERENT DIVISIONS

Each row's steps are spaced proportionally to its division. A kick at 1/4 fires 4 times while a hi-hat at 1/16 fires 16 times in the same bar. They share one timeline.

SAMPLE LIBRARY

18 sounds.
Zero network.

Every library sample is synthesized locally via OfflineAudioContext — no CDN, no CORS, no waiting. Load your own files on top of any slot.

KICKS — 4 SOUNDS

808 Kicksub sweep

Deep Kicklow body

Punchy Kickfast sweep

Vinyl Kicksaturated

SNARES — 3 SOUNDS

Crack Snarebright

Fat Snareshaped noise

Rimshotmetallic

HI-HATS — 4 SOUNDS

Tight HHclosed

Crisp HHpartials

Open HHlong decay

Sizzle HatFM shimmer

CLAPS — 2 SOUNDS

Snap Claptight

Room Clapshaped

PERCS — 5 SOUNDS

High Tompitch sweep

Floor Tomdeep

Ride BellFM synthesis

Crashshimmer

Load your own samples

Replace any row's synth with your own audio files. Three ways to load:

↑Upload button in the sample browser panel

⬡Click the ⬡ synth label under any instrument

⤵Drag any audio file from your OS onto a row

Programmatic API

Load buffers directly in code. Session state saves sample names and source type. Library samples re-render from the same function on restore.

Synth fallback

Clear any sample slot with ✕ to instantly restore the built-in synthesis. No row is ever broken — there's always a sound.

GET STARTED

Three lines
to make beats.

Standalone, npm, or React. Works everywhere the Web Audio API does — Chrome, Firefox, Safari, Edge.

// npm
npm install wavr-drum-machine

// import
import DrumMachine from 'wavr-drum-machine';

// mount
const dm = new DrumMachine({
  audioContext: new AudioContext(),
  bpm: 128
});
dm.mount(document.getElementById('container'));

// handle bounce
dm.onRender = (audioBuffer, bpm) => {
  // AudioBuffer ready to use
};

// load a sample programmatically
dm.loadSampleBuffer('kick', buf, 'My Kick');

// per-row step division
dm._stepDivs.hhc = '1/32';  // hi-hat → double-time
dm._stepDivs.kick = '1/4'; // kick → one per beat

Browser	Web Audio	Offline Render
Chrome 66+	✓	✓
Firefox 76+	✓	✓
Safari 14.1+	✓	✓
Edge 79+	✓	✓
iOS Safari 14.5+	✓	✓

INSTRUMENT IDs

kick

Kick drum

snare

Snare

clap

Clap

hhc

Hi-Hat Closed

hho

Hi-Hat Open

tom_hi

Tom Hi

tom_mid

Tom Mid

ride

Ride

DRUM/MACHINEWAVR PRO

Every feature.No server.

Polyrhythmout of the box.

18 sounds.Zero network.

Three linesto make beats.

Make somethingright now.

DRUM
/MACHINE
WAVR PRO

Every feature.
No server.

Polyrhythm
out of the box.

18 sounds.
Zero network.

Three lines
to make beats.

Make something
right now.