music visualizer, played live

Load a track and a cover, and spectrum bars or an oscilloscope move with it. You play it live and record the take.

open spectrum bars →

it is not
An upload-and-render tool. No render queue, no templates, no lyric captions, no batch. For hands-off, look for an automated audio-to-video renderer.
what comes out
An MP4 of the canvas with the loaded track in sync, recorded in real time. Stills as PNG or vector paths.
price
The audio-reactive effects, spectrum-bars included, are paid. Every effect previews free with no account, and a free set exports. $59 once, for the web studio and the macOS app, with no subscription.
where it runs
In the browser, on your own machine. Nothing uploads.

01/ MAKING

what making one actually looks like

It happens in one browser tab, in this order.

  1. 01

    give it something to look at

    SOURCE

    The picture is a still image, a video file or a live camera. Album art is the obvious still, and a good one: spectrum-bars tints its bars with the source image, so the cover’s own colours end up in the graph rather than a stock gradient.

  2. 02

    load the track

    AUDIOFILE

    Drop an audio file in and it plays on a loop while you work. That file is what ends up in the recording.

    The microphone and system audio can drive the visuals when the track is coming out of a DAW or a browser tab, but kott only listens to them: a take made from either is recorded without that sound.

  3. 03

    pick the effect, then route the bass

    ADD

    spectrum-bars is the classic bar graph, oscilloscope draws the waveform, and both move with the track before you set anything. Then route a bass band onto one control, the bars’ SCALE or GLOW, press ADD and set the depth. Now the kick moves that one control and nothing else.

  4. 04

    record the track through

    VIDEOR

    Press VIDEO (or R) and play the track through. The canvas is written to an MP4 with the audio in sync, or WebM in a browser that cannot write MP4. Anything you move by hand while it runs is part of the take.

    Stills come out as PNG, and vector paths are available for print and plotters.

02/ VISUALS

the visuals that read the audio directly

These take the spectrum or the waveform as their input, so they move the moment a track is playing, before you have set anything.

  • spectrum-bars

    A vertical FFT bar graph: the low end on the left, the air on the right, each bar as tall as the spectrum at that frequency. The source image tints the bars, and a soft peak cap glows on top. The effect most people mean by music visualizer.

  • oscilloscope

    The time-domain waveform, drawn as a glowing trace with a gaussian bloom. It shows the shape of the wave rather than which frequencies are present, so it reads tighter on sparse material: a solo voice, a synth line, a kick with space around it.

  • radial-spectrum and freq-rings

    The same spectrum wrapped around a centre: spokes out from the middle, or concentric rings. Both suit a square crop and album art better than a horizontal graph does.

  • reactive-warp and signal-wave-plus

    These push the source image around with the audio, so the picture bends and ripples instead of a chart appearing over it. The route to something that does not announce itself as a visualizer.

  • datamosh-real

    Compression artefacts driven by the audio: blocks smear and the frame tears where the signal spikes. The loudest option here, and the one that most needs a parameter routed by hand.

  • and everything else

    Halftone, dither, glitch and the rest do not read the audio on their own, but every control they have is a route destination, so any of them can be made to move with the track.

03/ ROUTING

you choose what the bass moves

Every tool in this space says “audio-reactive”. The question worth asking is which signal reaches which control, and whether you get to decide.

audio · routes120 bpm, demo clock
  • bassrideSCALEspectrum-bars
  • bardownbeattriggerGLOWspectrum-bars
  • swellbuild · droprideGAPspectrum-bars

  • what kott hears

    beyond the raw spectrum

    Spectral-flux onset with a phase-locked beat pulse. A downbeat on the first beat of every four-beat bar. A build-and-drop meter. Tempo tracked between 60 and 180 BPM. Bass, mid and treble as separate signals, plus 2 to 8 EQ bands you define yourself, each with its own frequency window and gain, behind one band gate.

  • any of those, onto any parameter

    a route per connection

    kott has no list of effects with the reaction baked in. A route picks a signal as its source and an effect parameter as its destination, with its own depth and smoothing. Every parameter of every effect is a valid destination, not only the ones on this page.

  • which is why it does not look like a preset

    the wiring is the work

    A template decides that the bars move with the volume. Here you decide that an EQ band moves the bar scale, the downbeat the glow, the build the gap, or something else entirely. Two people using the same effect on the same track make different pieces.

  • or a physical fader

    webmidi, nanokontrol2

    A MIDI controller works in the browser with nothing installed. A nanoKONTROL2 map ships with kott and any control MIDI-learns onto any parameter. A take recorded with one hand on a fader comes out different from one that runs itself.

04/ LIMITS

when kott is the wrong tool for this

“Music visualizer” covers more than one job, and most tools in the results do the other one. Here is when yours is the other.

  • you want to upload an mp3 and get a video back

    kott has no render queue and no upload step. The audio plays on your machine, the visuals are drawn live from it, and a file exists only once you have recorded one, in real time, at the length of the track.

  • you want a template or lyric captions

    No template gallery and no preset scene to drop a track into. kott does not read lyrics or sync text to a vocal; anything typed on screen is typed by you.

  • you want a batch

    There is no queue and no way to point kott at ten tracks and come back later. One track, one performance, one recording.

  • you want it free and automatic

    Every effect previews free with no account, and a free set exports without paying, but spectrum-bars and the rest of the audio spectacle need the one-time licence. For free and hands-off, look for an automated audio-to-video renderer, a different and reasonable kind of tool.

  • you want 3D or particles

    The visual language is narrow on purpose: dither, halftone, print, ASCII, engraving, glitch, CRT. No 3D, no generative geometry, no particle scenes. It is not a video editor either: no timeline, no cuts.

  • you need it inside another app

    No NDI, no Syphon, no virtual camera, so kott cannot appear as a source in another application. OBS can still capture its window. The offline native build is macOS only; on Windows and Linux, kott is a browser tab with WebGL2.

05/ FAQ

questions

how do I make a music visualizer?

In kott: pick a visual source (a still image such as album art, a video file, or a live camera), load your track as an audio file, and choose an effect that reads the audio: spectrum-bars for the classic FFT bar graph, oscilloscope for the waveform. Then add a route so a signal you choose moves a parameter you choose. Press VIDEO and play the track through; the canvas is written to an MP4 with the audio in sync, so the recording is the take you performed. There is no upload-and-render step: the visuals are drawn live and you capture them.

is there a free music visualizer?

In kott, every effect previews free with no account, and a free set exports without paying, but the audio-reactive effects, spectrum-bars included, need the one-time licence. So you can open the studio, load a track and watch the bars move for nothing, and paying is what lets you record it. If you need free and fully automatic, what you want is an audio-to-video renderer that takes an upload and returns a file, which is a different kind of tool.

can I use my own song?

Yes. kott takes an audio file you load from your own disk, and that is the input that gets recorded into the MP4. It also listens to a live microphone or system audio if the track is playing out of a DAW or another application, but those drive the visuals without being recorded. The audio is decoded and analysed in your own browser, and nothing uploads.

can I make a music visualizer in a browser?

Yes. kott runs in any browser with WebGL2, with nothing to install and no account needed to look. The spectrum analysis, the effects and the recording all happen on your machine. There is also a native macOS app that runs fully offline, covered by the same one-time licence as the web studio.

does it export video?

Yes. The VIDEO button writes the canvas to an MP4 with the audio in sync, recorded in real time as the track plays. Stills come out as PNG, and vector paths are available for print and plotters. There is no batch export and no render queue: one take at a time, at the length of the material.

what makes it different from a template visualizer?

The reaction is not decided for you. kott derives spectral-flux onset, a phase-locked beat pulse, a downbeat, a build-and-drop meter, tempo between 60 and 180 BPM, bass, mid and treble, and 2 to 8 EQ bands you define yourself, and any of those signals can be routed onto any parameter of any effect with its own depth and smoothing. You choose what the bass moves. That is also the cost: nothing looks finished until you have wired something.

06/ NEXT

nearby pages, and what each one answers

07/ OUT

put a track through it

The studio opens on spectrum-bars. Drop in an audio file and a cover image, and the bars are already moving with the track. The quickest way to find out whether a live visualizer is what you wanted is to watch one answer your own song.

open spectrum bars →

try
Free preview in the browser, no account, no install.
licence
$59, once. Web studio and macOS app, no subscription.
your track
Decoded and analysed on your machine. Nothing uploads.