svemlr: mlr in the browser


mlr in the browser

i have been working with @halvves’ excellent webmonome library to make a version of (the max/msp) mlr for web browsers. it’s not yet complete, but is useable.


  • [NEW] key presses via QWERTY keyboards
  • sample looping, loop points, and reverse playback
  • sample cutting
  • 4 groups (with level/mute controls via grid)
  • 2 pattern recorders
  • quantized button presses
  • mlr-orange


  • record live audio input
  • presets and saving configuration
  • keyboard shortcuts
  • tap tempo
  • sync
  • improve layout/styles


  • chromium-based browser (e.g. chrome, edge) due to webusb support
  • grid (currently only tested on a new 128 and a walnut 64—testers welcome : )
  • serialosc disabled (instructions to disable/re-enable included)

Download | source code

Edit: reformatted and recategorised for Library



This is a dream come true! Finally I can run mlr on a computer without using max. Will try this asap for sure. (I also have a walnut 64)

Glad to hear! :slight_smile:

It’ll be interesting to see how browsers cope with processing live audio. It feels like they’re missing some key Web Audio APIs (e.g. playback position, but I’m excited about how we can use modern browser technologies (e.g. WebRTC / Web Sockets), to make music.

Let me know how it goes!

yes i agree! i feel like browser based music tools are overlooked as gimmics, but it’s getting powerful. this is also a space i wanted to explore but still taking baby steps.


svemlr v0.2.0 now allows for grid input via qwerty keyboard (so no need for a monome grid).

The qwerty32 device emulates a monome grid by triggering keydown/keyup events for 32 keys as follows:


So for example, with svemlr, pressing q starts looping the first sample; 1 switches off the first group.


For some reason I can’t get my Grid 128 (new version) to work. I even uninstalled SerialOSC altogether as I didn’t know how to disable it on a Windows 10 PC… I’m using the latest version of Chrome, and I’m stuck on the device selection page…
Works great with the Keyboard though !

Thanks for trying it out, and sorry it hasn’t worked for you. I’ve only tested it on macOS browsers, so I’m guessing it’s an issue with Web USB support on Windows-based browsers? :confused:

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thank you again for this! it’s working great with my monome walnut 64. especially with that throwback UI, i really feel transported back to 2009 <3

great job! let me know if i can help in any way, (i’m also a web developer)


Oooh…this looks very exciting.

What is the easiest way to route the audio output inti Ableton Live?