The Best Free Mastering Software Tools For Windows & Mac!


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)

  • DuckEQ by HeelAudio (Mac)
  • IQ4gui by Platinumears (Windows)
  • TDR Nova by Tokyo Dawn Labs (Mac, Windows)

Equalizer (Coloring)

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 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 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 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 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 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.

To round things up, here’s a nice video introduction to Limiter №6, created by Vladislav Goncharov (the developer) himself. It shows the basic methods of using this fantastic limiter to get the best results:

And that’s it! Please let me know if I’ve missed some good freeware effects or tools which you use for mastering. I will update the article in the future with more useful info, but you’re welcome to post your suggestions in the comments section below.

Many thanks to our reader Joe Helias for suggesting a ton of excellent plugins that are now included in this list. Thanks so much for the support, Joe!

Also, please share this article on your favorite social network, as well as your favorite forums and blogs. Thanks for reading BPB and happy mastering!

Share it like a boss.

About The Author

Tomislav is a journalist, music producer and web designer from Belgrade, Serbia. He is also the owner and editor-in-chief here at Bedroom Producers Blog.


    • Bedroom Producers Blog


      nice, i’ll give Maxwell Smart a try. never used it myself, but it seems that people really like it over at KVR.

      also, thanks for suggesting JB stuff, i completely forgot about those!

      • The MAnalyzer is a good alternative to the SPAN with some extra features like sonogram.
        Then there’s also the MStereoscope and the MLoudnessAnalyzer in the free bundle, but I haven’t checked them yet.
        I also like the old but good DFX RMS buddy for metering purposes.

    • Bedroom Producers Blog


      you’re right! i’ve just added Smash Pro, Barricade Pro and Broadcast to the list.

      awesome tools! thanks for reminding me Irion!

    • Bedroom Producers Blog


      it’s more of a gimmick than a serious mastering tool, but it can work as a nice little exciter/booster on certain occasions. it’s basically a preset version of IL Maximus.

      btw, i have no idea, which song is it? :)

  1. Thanks for including ClipShifter on this list. It is great to be included on a list with such venerable plugins. I do want to mention that ClipShifter is now on version 2.1 (soon to be 2.2). I also have OSX support (AU, VST, and VST3).

    • Bedroom Producers Blog


      hi Matt, no poblem! thanks for sharing such great freeware with us!

      i’ve updated the list with the fact that ClipShifter now also offers Mac support.

      please share this article if you can and thanks for reading BPB!

  2. these kinds of posts are my favorite. know why? Because young producers will google certain phrases like “mastering tools,” and poof they’ll come across the humble bedroomproducers blog that has given such great information about new plugins and production.

  3. You really should link this article from your VST Plugins page to make it easier to find. Great content and plugin ideas. Thank you for another useful article!

    • Bedroom Producers Blog


      good idea!

      i’ll do it as soon as i come back from my holiday. the connection is quite crappy atm. :)

  4. from the You Wa Shock product page that you linked:
    “You Wa Shock !

    Make it truck shine !

    You Wa Shock ! is VST/Winamp effect for brighten up and maximize any truck you hand him.

    Use: Though nothing can bring back the missing particle You Wa Shock ! strength is in the behind parts. Excrete excite sound for your trucks. Push harder for more excite sound. The knob will go up. You can operate You Wa Shock ! as early as possible in the truck or to be late. The 4 A B C D fixings create new crunch excrete. Listen for a happy sound.”

    What’s up with this?

  5. I Use a good bit of these daily. I live in Nashville Tn. and mix and master as a big part of my income. I had completely forgotten about the Baxter EQ and I don’t know why….. Just downloaded it and applied to a couple mixes that I did recently…. and was totally impressed… I was taught that anyone can slam a mix to the limit, but if the EQ is bad,,, you just have a loud track with no quality.