Free Track Mastering Online

Drag and drop your audio track and have it mastered online instantly within the browser for free. No upload or download required, 100% in browser and awesome sound ideal for demos, streaming and release.

Drop & Drop
Select track


If you like what you hear then please share this site with your peers!


This site is currently an Alpha version 0.4.4 and only showcases limited functionality


How does online mastering work?

The mastering app leverages a new technology that has been adopted by many browsers called WebAssembly which allows us to compile our C++ DSP libraries and get native performances for signal processing.

The mastering app uses a successful mix chain from my automated mastering system Blackbox. This chain does a fantastic job of using AI to predict what a mastering engineer would do and as a result gives an authentic analog sounding master to almost any genre of music or style of track.


Simply drag and drop your track into the target circle and the App will instantly start to master your audio. Leave the browser open as it is a container for the application to run within. A progress bar will appear and show how close the master is to completion. Once finished select your output bit rate and click the SAVE button to save you master to your computer.


  • AIFF file format support
  • Multiple sample rates (not just 44.1khz)
  • A / B preview on certain browsers
  • Adjustable settings for overall Loudness, Brightness and Quality
  • Adjustable output bitrate 16bit / 24bit PCM or 32bit floating point
  • Use threading when all Spectre issues are sorted
  • Use SSE performance enhancements to speed up processing

Known Issues

As this is an experimental project using bleeding edge technologies we are aware of compatibility issues with some vendors. As such we recommend using the latest version of Chrome or Edge for best results

  • Aware of issues with Safari and Firefox
  • Aware of issues on some macs