A
B
Phones
Sampler
Beat viewFile decks only. Ticks line up when the decks are in time.
One-press publishing with the tracklist filled in arrives once SoundCloud, Mixcloud and YouTube approve the connections.
Press Connect, then pick a preset, run Guided set-up, or use Learn next to any control and move or press the matching control on your hardware. Mappings are kept in this browser.
| Control | Deck A | Deck B | Mixer |
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About browserdj · Source and issues on GitHub · Controllers · Privacy
Your files stay on your machine. Tracks are decoded and analysed inside this browser tab and are never uploaded anywhere. Apart from optional usage analytics, which only run if you allow them when asked (change your choice), the page makes no network requests once it has loaded. The library below remembers the folder you point it at and caches BPM, key and loudness locally so the next session opens instantly. Works best in Chrome or Edge on a desktop or laptop. Once it has loaded over the web it keeps working offline, and Chrome's install option in the address bar pins it to your dock or taskbar.
Finding your way around. The two lanes at the top are the decks' waveforms: scrolling detail above, whole track below, with the playhead in the middle. Under them sit the decks either side of the mixer. Each deck shows the essentials (BPM and key, Sync, Cue and Play, hot cues, loops and jumps); press More on a deck for the finer controls: pitch fader, position slider, manual loop In and Out, loop resize, jump size, Beat 1 and the /2 and x2 grid tools, Q quantise, Slip, and the crossfader assign on that channel. The bottom bar holds the sampler, the crossfader and the headphone controls. Library in the header opens your music full screen and closes again when you load a track; Mixer set-up slides in the mixer profile, crossfader law, auto gain, recording format, BPM range, the web sources switch and the beat view; MIDI / System holds the controller mapping together with Test tone, Backup and Restore.
Backup and Restore (under MIDI / System in the header) save and reload everything this browser keeps for you: hot cues and loops per track, the main cue point, MIDI mapping, mixer profile, crossfader assignments and the other settings. Browsers store these per site, so take a backup before clearing browsing data or moving to another computer or address. The library's analysis cache is not included; it rebuilds itself from your files.
File decodes a local audio file into the mixer. Everything works: waveform, pitch fader, EQ, filter, effects, metering, recording. Each file gets a beat grid (BPM to two decimals, beat positions and a downbeat guess) when it loads; a ~ before the BPM means the analyser wasn't sure. Sync is a lock: while lit, the deck follows the other deck's tempo (even if you move the master's pitch fader) and holds the beats in phase. Pressing it lines the beats up once, then the lock keeps them there. Touch the pitch fader to take manual control again. The other deck's BPM box shows Master. Hold a Nudge button to slip a few percent while you listen, use Beat 1 at a downbeat if the four dots are out of step, and /2 or ×2 if the grid locked onto half or double time. The BPM range in Mixer set-up tells the analyser which tempos to consider: 70 to 140 suits house and techno; pick 88 to 175 for drum and bass or double-time trap. The beat view in Mixer set-up shows both decks around their playheads: when the ticks line up, you are in time.
Web sources (off by default). Tick YouTube and tab capture in Mixer set-up and each deck gains two more sources. YouTube embeds YouTube's own player: the deck drives play, cue, seek, speed and the fader, but the browser keeps the embed's audio out of reach, so EQ, filter and effects are bypassed on that channel, and it only plays when the page is served from a web address rather than opened as a file. Capture (desktop Chrome or Edge) pulls the audio of another browser tab into the mixer with the full EQ and effects chain: open the video in its own tab, press Capture, pick that tab and tick "Share tab audio". Nothing is fetched from YouTube until you load a video.
Cues. CUE is the main cue: press while stopped to set it where you are, press while playing to jump back and stop. The four numbered pads are hot cues: press an empty pad to set it, press a set pad to jump there and play, hold it (or shift-click, or right-click) to clear it. Hot cues are remembered per track, in this browser, so they come back when you load the same file or video again. With Q lit, new hot cues on file decks snap to the nearest beat.
Mixer and EQ. Each channel has three vertical EQ faders (five in the four-band profile) with a KILL button under each: press it to drop that band out completely and press it again to come back to where it was. Filter, effect Amount and Wet are horizontal bars under the faders and effect select. Double-tap any fader or bar to reset it. The Mixer select in Mixer set-up changes the mixer's character. Club 3-band isolator splits each channel into bands with crossovers at 250 Hz and 2.5 kHz and lets you kill any of them cleanly (DJM isolator mode). Classic shelving is the softer +6 / -26 dB EQ-mode sound. Four-band 92 style adds separate low-mid and hi-mid bands with crossovers at 120, 650 and 3000 Hz, deep cuts rather than kills on the mids, and a more resonant filter. Battle mixer gives sharp fader and crossfader cuts. With More switched on, the A / Thru / B switch under each channel assigns it to a crossfader side or takes it off the crossfader entirely, which is how most house DJs run a club mixer: both channels on Thru and mixing on the channel faders. X-fader in Mixer set-up picks the crossfader law.
Waveforms and FX. File decks show a scrolling waveform (bass in the deep colour, mids in the deck colour, highs in white) with beats, bars, cues and loops, plus the whole-track overview under it. Drag the scrolling waveform to move the track by hand: while paused it slides under the playhead with a short scrub so you can line up a kick, then Cue sets the point there (hold Shift as you let go to snap to the nearest beat; the mouse wheel moves it in fine steps). While playing, dragging bends the tempo like a jog wheel. Click the overview to jump. Echo and Gate follow the deck's tempo in beat divisions set by the Amount knob; Noise Sweep adds a resonant noise sweep on top. Brake stops the track like a turntable being held; Rev plays backwards while held. Sampler pads in the bottom bar fire one-shots into the master (press + to load a sound). Auto gain evens out track levels from the analysis. Rec can capture WebM or lossless WAV (up to 45 minutes).
MIDI. Press MIDI / System in the header, Connect, then Learn next to any control and touch the matching knob, fader, pad or button on your hardware. Pads and buttons map to notes or CCs, faders and knobs to CCs, jog wheels to relative CCs (bend while playing, scrub while paused). Hold a pad mapped to "Clear hot cue" while pressing a hot cue pad to clear it. Copy map and Paste map move a mapping between browsers. Any MIDI controller. Pick it from the Presets list if it is there (a known controller is offered automatically when you plug it in), or run Guided set-up, which asks for each essential control in turn and works out deck B from deck A, so a new controller takes about two minutes. Import file takes a browserdj preset or a Mixxx .midi.xml mapping, and Save as file turns your mapping into a preset you can keep or send in for the library. Hold your controller's Shift button while learning to map a second function to a control; pitch faders that send 14-bit pairs, encoders of every encoding, inverted controls and soft takeover are all handled, and button lights follow the decks over MIDI out. Traktor Kontrol X1 MK1 and Kontrol Z1 need no MIDI and no Native Instruments software: the buttons in the same panel talk to them directly over USB (Chrome or Edge on a computer; the browser asks you to pick the device the first time and remembers it). Load the preset for each, or map anything with Learn exactly as for MIDI. The X1 preset covers Play, Cue, Sync, CUP as Slip, loop In and Out, beat jumps, the four hot cue buttons (hold Shift to clear), the browse encoders for the library with push to load, the loop encoders for loop size with push for exit and reloop, the FX buttons for next effect and effect on or off, and the dry/wet and first knobs for effect wet and amount; knobs 2 and 3 are left for you to Learn. The Z1 preset covers gain, EQ, filter, channel faders, crossfader, cue mix, the cue buttons and FX on or off. The X1's lights follow play, sync, loops, hot cues and effects; the Z1's VU meters, cue and FX buttons follow the mixer. To use the Z1's headphone socket, make the Z1 the Mac's sound output and set Phones to "4-channel interface"; the Z1's cue mix knob then blends cue against master.
Headphones. Each channel has a Phones cue button that sends that channel to the phones bus before the fader. In the bottom bar, Phones chooses where that bus goes: Split cue uses your one output with cue in the left ear and master in the right (a Y splitter cable does the rest), or press Pick device to send the cue to a second output such as a USB interface or Bluetooth headphones (Chrome asks for microphone permission only to show device names). Cue/Mst blends cue against master in the phones, Phones sets their level.
Key lock. The Key button next to the pitch range is master tempo: with it lit, the pitch fader, Sync and Nudge change speed without changing the key. It adds about 60 ms of delay to that deck, which the sync lock already accounts for, so leave it on for both decks or off for both if you are matching by ear.
Loops and jumps. The 1, 2, 4 and 8 pads set an auto loop of that many beats from the current beat (press the lit pad again to exit). In and Out set a manual loop; Exit leaves it and Reloop brings the last loop back; ½ and ×2 resize it while it plays. Hold a Roll pad for a momentary loop that lets go back to where the track would have been. Jump moves by the chosen number of beats in either direction, keeping the beat phase, and drags an active loop along with it. Slip makes loops and hot cues temporary: the track keeps running underneath, and when you let go it carries on from there (hot cue pads play while held in Slip mode).
Shortcuts on a keyboard: Q play/pause A, P play/pause B, A cue A, L cue B, 1 to 4 hot cues A, 7 8 9 0 hot cues B (with Shift to clear), S / K 4-beat loop A / B, D F jump A, J ; jump B. Double-tap any fader or bar to reset it.
No sound? Press Test tone (under MIDI / System). If you hear the beep, the engine and your output are fine and the problem is with the deck source: a YouTube video that blocks embedding shows a message under the player. If you hear nothing, check the box at the top of the page, your output device, and on an iPhone the ring/silent switch.
| Title | Artist | BPM | Key | Step | Length | Genre | Load |
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Open a folder of music and every track gets analysed in the background: BPM, beat grid, key and level, cached so it only happens once. Then search, filter by BPM or key, or show only tracks that mix with what's on a deck, and load straight to A or B. Mix order chains whatever is listed into a playing order where each step is a small tempo move to a compatible key; select a track first to start from it, and the Step column says why each track follows the last. Nothing leaves your computer.