Synthesizer visualizer for hardware and software synths
Run a hardware synth into your interface, point it at the microphone, or play the built-in synth from a MIDI keyboard: filter sweeps, LFOs and resonance all show up in the picture. Free, browser-based, nothing to install.
Who this is for
- Synth and modular players
- Sound designers who want to see a filter move
- Anyone streaming a jam or a patch demo
A filter sweep is a visible thing
The 96-band logarithmic spectrum shows exactly where the cutoff sits and how sharp the resonance peak is, while Oscilloscope draws the raw wave, so you can watch a square wave round off as the filter closes. An LFO becomes a regular motion in both.
Three ways in
An audio interface gives the cleanest signal. The microphone works for a desktop synth with a speaker. If the synth is a plugin, route it with a virtual audio device (BlackHole on Mac, VB-Cable on Windows) and pick that as the input. Free play’s own five instruments — Keys, Pluck, Bass, Pad and Bell — are there when you just want to play something immediately.
MIDI learn for the visuals themselves
In Tune → MIDI you can arm Learn, move a knob on your controller, then move the slider you want it to own. That CC controls intensity, glow, trails or whatever you bound it to from then on, and the binding is remembered in your browser. The same controller that plays the synth can shape the visual.
How to do it
- Open BLOOB and click “Mic / instrument”, then choose your interface
- Play a patch and sweep the filter while watching Spectrum Bars or Signal Ridges
- Open Tune → MIDI, press Learn, move a knob, then move the slider it should control
- Record a clip, or press H and play fullscreen
Questions people ask about synthesizer visualizer
Can I visualise a plugin synth from my DAW?
Yes, with a virtual audio device selected as the input — or share the browser tab if it runs in a browser.
Does MIDI learn need a driver?
No. Chrome or Edge with Web MIDI permission is enough, and the bindings are stored locally in your browser.
Is the input analysed in stereo?
No, the channels are mixed to mono for analysis. It does not change what you hear — BLOOB only listens.
Modular rigs?
Yes, take a line out into your interface. Set the level so peaks stay below clipping; the analyser adapts to quiet signals, but not to a distorted one.
Related: live instrument visualizer · midi keyboard visualizer · oscilloscope music visualizer · vj software free