Finding great mastering plugins isn’t always easy. 

Luckily for you, we’ve created a list of some of the best mastering plugins on the market today. The best thing is that all of these are completely free!

Without any further ado, let’s dive in and check out the ten best free mastering plugins on the market. 

1. TDR Kotelnikov

Many mastering compressor plugins try to emulate existing hardware units. The beauty of TDR Kotelnikov is that it does the totally opposite. 

This purely digital plugin uses a number of complex algorithms to give you the most control over the dynamics of your mix without adding any color. 

The thing that separates this compressor from other compressors is that it utilizes a frequency dependent ratio. This unique function allows you to set different compression ratios based on the incoming signal’s frequency. 

You’ll also find a handy Low Frequency Relax feature, which allows you to utilize your side-chain with a high-pass filter. This feature is great for EDM, as it keeps your compressor from reacting too much to low frequencies, such as kick drums and basses. Essentially, you have the ability to effectively lower your threshold without squashing your mix. 

Lastly, you have the ability to process your mid and side channels separately. 

PRO TIP: I often find myself using two instances of this plugin, one to work on the mids and the second to work on the sides. 

I truly can’t find a reason why I wouldn’t recommend this mastering compression plugin. 

2. D16 Group – Frontier

If you need a high-quality limiter to get your mixes up to loudness standards, then we highly recommend the D16 Group Frontier plugin, which is basically a compressor that has been taken to the extreme with a high ratio. 

The soft clip switch sounds excellent, allowing you to add subtle harmonics to your mix without imparting any distortion. You also get your typical output knobs and threshold with automatic makeup gain. 

Though it has a “limiter” title, it works just as well as a compressor. You can use the control input knob to control whether you want the mid channel, the side channels, or both affected.

Overall, under the hood, this self-adaptive compressor works great for just about any kind of mix. 

There are plenty of great presets to get you started too.

3. Tokyo Dawn Labs – SlickEQ

Slick EQ came from a collaboration between Tokyo Dawn Labs and Variety of Sound. While you can certainly use SlickEQ for mixing, it was primarily made for mastering, focusing on its a musical sound, total flexibility, and ease of use. 

You get three filter bands going from low to mid to high in a semi-parametric style. The plugin also gives you four unique EQ modes that you can quickly access, making for an intuitive workflow. Each of these EQ modes works with distinct curves and behavioral settings.

One of the neat things about this plugin is that it uses an automatic gain compensation function that you can use to automatically adjust the perceived loudness of the plugin. 

Another cool feature of SlickEQ is that you can use it to process either the middle signal or the side signals independently. 

What truly sets this plugin apart, however, is the output stage, which has four separate saturation models that you can use to add subtle warmth and textures. 

If you end up liking the plugin, you can upgrade to the Gentlemen’s Edition, which comes with a few additional saturation modes and EQ functions. 

4. Tokyo Dawn Labs – Nova EQ

If you want a bit more surgical control over your master EQ, you can use Tokyo Dawn Labs Nova EQ, which provides users with a complete dynamics section. 

This means that you can use this EQ to balance between frequency and dynamic functionality. 

While the interface might look a bit intimidating upon first glance, the layout is actually quite easy to navigate with a number of intuitive controls. Even beginners will find it easy to use. 

You’ll find a classic knob interface and an easy drag-and-drop design to make accessing the controls you need as smooth as possible. At each end, you have great-sounding high-pass and low-pass filters. 

Overall, Nova EQ is a very high-quality plugin, and we would even download it if it wasn’t free. 

5. Klanghelm – IVGI

Klanghelm offers some of the best plugins on the market today. I constantly find myself using their compressor plugins, however, this saturation plugin is equally as strong. 

One of the best ways to give any mix an overall boost of warmth and character is with saturation, and dialing in a bit of the Klanghelm IVGI can completely alter your mix in the best way possible. 

Not only can you add warmth with IVGI, but you can also use it to add distortion. If the plugin isn’t reacting quite how you want it to with your mix, you can always use the Response control to alter the saturation plugin’s frequency dependency. 

Overall, it’s a wonderful plugin for any mix that is lacking warmth. 

6. YouLean Loudness Meter 2

If you’re in need of a free loudness metering plugin with multiple meter modes to keep track of the loudness of your mix, we recommend checking out YouLean Loudness Meter 2. Even with its free price tag, it is one of the most accurate loudness meters that I’ve ever used. 

Even when I compare how it works with other premium metering plugins, I can’t find much of a difference. This is likely why so many professional mastering engineers use it. 

Of course, you can always upgrade to the pro version if you want additional features. 

It’s a truly essential tool for any producer or mastering engineer who wants to visualize the loudness properties of their mix without sacrificing dynamic flexibility. 

With a real-time visual interface that uses a high-quality design, not only are you able to hear what is happening with you mix, you can also see it too. This makes it a great tool for beginners who want a better understanding of what is happening in their mixes. 

You’ll also find a wide range of presets to get you going, perfect for making sure your music sounds how it should on all of the best streaming platforms, including YouTube, Spotify, and more.

7. Wave Arts Tube Saturator Vintage

The Tube Saturator Vintage plugin by Wave Arts is a unique saturation plugin that uses circuit emulation technology to reproduce a dual triode preamp sound.

This plugin sounds absolutely fantastic, giving you plenty of built-in features, including a handy “fat” switch and a three-band EQ, which you can use to breathe a bit more life into your sound. 

After spending some time using Tube Saturator Vintage on a number of mixes, I have to say that one of my favorite ways to use it is for mastering. This is because it does a wonderful job at imparting a slightly warm tone to your overall mix without adding distortion. 

One of the main drawbacks of this particular plugin is that it is very CPU-intensive, due to the circuit simulation technology. Of course, with a plugin that captures the sound of every single analog circuit in the original hardware, the heavy CPU usage might be worth it. 

8. TBProAudio mvMeter 2

mvMeter 2 from TBProAudio is a multivariable meter that includes measurement for PPM, VU, EBUR128, and RMS. You’ll also find multi-channel metering capabilities, which you can use to see what is going on with your sound on every part of your mix, including the mid, left, right, and side channels.

There are five different themes to choose from. Though they don’t sound different, it can be nice to have an aesthetic choice if you want one. 

Here are some of the most important features found on this plugin:

• Adjustable meter delay
• Single and dual-meter display
• Adjustable reference levels for every metering mode
• Preset management 

9. Flux – Stereo Tool V3

Stereo Tool V3 is a great free mastering plugin for getting precise control over your mix using the input gain and the left and right individual panning channels.

The sleek and modern interface utilizes accurate visual feedback and shows you more about the content running though it using a number of tools.

Some of the main features on this plugin include the input and output PPM meters, the vector scope, and the phase correlation meter that permanently monitors the individual signals from the left and right.

Overall, Stereo Tool V3 is a wonderful plugin that you can use to solve a number of potential issues in your mix, whether you are having phase issues or you’re dealing with a stereo image balance issue. 

10. Tonmann De-Esser

While most people think of de-essers as mixing plugins to get rid of sibilance on vocals, they can be equally as capable for getting rid of harshness in mixes.

One of my favorite ways to use Tonmann De-Esser is to get rid of strange or artificial sounds that are poking through the mix. The beauty of this de-esser is that it is extremely transparent, meaning you don’t get any of the weird artifacts that you might get with others. 

It’s also very easy to use, as it only features a small handful of controls, including a bandwidth, a center frequency, threshold, Lookahead, release, attenuation, a low-pass filter, and a wide-band filter. Overall, the plugin is ultra-simplistic, great for beginners who are just getting use to using de-esser plugins. 

Some of the main features of this plugin include:

• A Lookahead feature that can get rid of unwanted sibilance or sharp transients
• An adjustable detection threshold you can use to retain your crisp and clear vocal sound
• A completely adjustable bandwidth and center frequency 
• Selectable low-pass and wide-band modes
• Dual mono mode and true independent stereo operation 

Final Thoughts

Hopefully, you have all of the information you need to start building a high-quality arsenal of free mastering plugins. 

Every plugin on this list is amazing in its own right, especially when you consider that none of them cost a dime.

Download them all and give them a try! 

If you want to learn more about mastering and start cranking out professional tracks from the comfort of your home or studio, make sure to check out our Mastering Start to Finish course. You’ll find 40+ lessons and tons of great extra to start mastering your music with ease.