The best freeware effects and tools suitable for use in audio mastering

After spending more than a year creating the Free VST Plugins section, I’ve decided to create a specialized list of my favorite free mastering software tools in VST/AU plugin format for Windows and Mac.

 I’ve listed all of the plugins which I use frequently while mastering tracks for the Reminiscence Audio label and sorted them by type for easy reference. There may be some better commercial plugins out there, but the freeware plugin scene is so strong nowadays that you can do a great mastering job without spending a dime.

Of course, you will need a properly treated room, as well as proper monitoring gear. And of top of that you will need lots of knowledge and experience in order to truly grasp the process of audio mastering. I can’t really help you with those!

But when it comes to free mastering software, this article will be a great starting point. Whether you’re an experienced mastering engineer or a beginner, you can use this list as an easy reference for refining your mastering chain.

Free Mastering Software List

This is a list of the best freeware effects and tools suitable for use in audio mastering. Use the links to visit the homepage of each product or scroll down to read reviews of my favorite free mastering software.

Equalizer (M/S)

Equalizer (Linear-Phase)

Equalizer (Dynamic)

Compressor (Clean)

Compressor (Coloring)

Multi Band Compressor





Transient Shaper


  • bx_solo by Brainworx (Mac, Windows)
  • MSED by Voxengo (Mac, Windows)

Spectrum Analyzer

  • SPAN by Voxengo (Mac, Windows)
  • Toscanalyzer by Dynamusic (Linux, Mac, Windows)


Mastering Suite

My Favorite Mastering Tools

In this section, I will say a few words about my personal favorite free mastering software effects and tools. These are the freeware effects which I swear by and which I use in everyday mastering tasks.

BaxterEQ by Variety Of Sound.

BaxterEQ is one of my favorite freeware equalizers and it is a superb tool when it comes to mastering. You can use the M/S mode to easily improve the stereo image of the mix at hand. I often use it to tame the lows boost the highs in the side channel. Of course, it can also be used in classic stereo mode, for fixing the bottom and high ends of your master.

TDR Feedback Compressor II by Tokyo Dawn.

TDR Feedback Compressor II is among the best software compressors for bus use out there. It is designed for highest quality 2-buss compression, using “feed-forward” topology for gain reduction.  This is a transparent compressor, meant for taming the peaks in a most natural sounding way.

Density mkIII by Variety Of Sound.

Density mkIII is my absolutely favorite compressor for adding a bit of crunch to a mix which is too clean. It can even be used as a saturation device. Simply increase the Drive knob setting, while reducing the Range amount to apply smooth saturation without gain reduction.

Limiter  №6 by Vladislav Goncharov.

Limiter №6 is an incredibly powerful freeware limiter. The signal goes through 5 different stages, each of which should be used to add a bit of gain reduction. This way you can get incredibly loud masters (not saying that going for a loud master is the best choice!) without that dreadful pumping effect. I use the multi-band setting in the limiter and clipper sections for best results.

SPAN by Voxengo.

SPAN is the legendary freeware spectrum analyzer released by Voxengo. No matter how confident you are when it comes to your ears, it’s never a bad idea to visually compare your work to another mastered track. The plugin comes with two factory presets, one of which is labeled Stereo Mastering and it’s the one you’ll need for this task.