Online Drum Machine - Free Beat Maker with 808 and 909 Kits

A step sequencer turns rhythm into something you can see: a row of boxes per drum sound, one bar split into equal steps. Light a box and that drum fires on that step, every time the pattern loops. The idea was made famous by Roland's TR-808 (1980) and TR-909 (1983), whose x0x-style button grids defined hip-hop, house, and techno — and this tool ships synthesized tributes to both, plus a hand-percussion kit, entirely in your browser. Every voice is computed live with the Web Audio API rather than played from samples, with recipes modeled on the classic analog voice circuits. The 808-style kick is a sine wave that dives from about 160 Hz down to 48 Hz in 80 milliseconds, rings out for more than half a second, gets a 3-millisecond filtered-noise click for attack, and passes through a gentle tanh waveshaper for analog-style warmth — accented hits ring slightly longer, just like driving the original circuit harder. The 808 snare layers two detuned triangle oscillators at 185 and 330 Hz under a snappy band-passed noise burst; the clap is three noise bursts 10 milliseconds apart plus a longer reverb-like tail; the metallic hats mix six square oscillators at the classic inharmonic ratios through a bandpass near 10 kHz; the cowbell is two square partials at 540 and 845 Hz through a 2.6 kHz bandpass; and the clave and rimshot are high-Q resonant-filter pings. The 909-style kit shares the architecture with a punchier, harder-driven kick, a pitch-dropping snare with extra sizzle, and hats that blend the metallic bank with noise, while the percussion kit tunes pitch-bent sine bursts into high, mid, and low congas and adds shaker, cabasa, rimshot, and clave. Because everything is synthesized on the fly, the machine loads instantly and works offline. The grid itself is flexible. Choose a pattern length of 8, 16, or 32 steps, and switch the feel between a straight grid (four steps per beat, classic 16ths) and a triplet grid (three steps per beat, for shuffles and 12/8 grooves). Pattern presets adapt to the feel too: every preset ships both a straight 16-step variant and a dedicated 12-step triplet variant, so Four on the floor becomes rolling triplet hats over a 4/4 kick and Rock becomes a true 12/8 blues shuffle instead of a chopped-up 16th pattern — and switching the feel while a preset is active automatically re-applies the matching variant. Patterns keep their first steps when you shorten the grid, so nothing is lost while you experiment. Each step cycles through three states — off, on, and accent — and accented hits play roughly 1.4 times louder, which is how real drummers make a hi-hat pattern breathe. Every track has its own volume fader (up to 150 percent) and a mute button for quick arrangement tricks. Timing uses a lookahead scheduler: a JavaScript timer wakes every 25 milliseconds and books upcoming hits directly on the audio hardware clock, about a tenth of a second ahead. That is why the groove stays locked even when you switch tabs. Swing pushes every second step on the straight grid late by a percentage of a step — the readout shows the exact delay in milliseconds at your tempo. When a loop is worth keeping, you have three options. Save it by name into your browser's local IndexedDB storage and reload it any time. Copy a share link — the whole pattern, kit, tempo, swing, and mixer state are encoded into the URL, so anyone who opens the link hears exactly what you made. Or export the loop as audio: the machine re-renders your pattern offline, including swing and accents, and downloads it as a WAV file or a 192 kbps MP3 ready for a sampler, DAW, or message thread.