Autotune is a popular pitch correction tool that has blown up to become one of the most recognisable, loved, and hated sounds of modern day music. It can be used aggressively to create that robotic “T-Pain” effect or more subtly to gently correct any vocal line to make it sound like it was sung perfectly.

How does autotune work?

In 1997 autotune was introduced to the world by a company called Antares. It was the first audio plugin that was able to change the pitch of vocals and other solo instruments without producing any artifacts or distortion.

If you look at an analogue signal or waveform it will look like one smooth, continuous line (see the light green line below). In the digital world, the analogue waveform will be broken down into samples at equal points along the waveform, the closer these samples are together, the higher the quality of the digital sound will be. This is what is typically known as the “sample rate”.

Autotune works by first altering the duration of each of the digital samples, and then changing the pitch of the sample such that the sample hits both the correct frequency and maintains the original duration. This process results in a natural sounding waveform even though it has been digitally altered.

This whole process requires advanced mathematics known as STFT (Short-time Fourier transform). Here is the wiki page if you’re interested in learning more: https://en.wikipedia.org/wiki/Short-time_Fourier_transform

But vocal pitch correction is not the only thing autotune is good for.

It can be used to pitch correct instruments like guitars and violins that may be slightly out of tune, shift the formant of a vocal to make it seem deeper and darker or higher more chipmunk-like. Some plugins even allow you to add vibrato.

I found a few other guides showing lists of free autotune VSTs but none of them seemed to have tested them. There were also plugins in their lists that weren’t even VSTs. So I decided to download a bunch of them and test them out for myself and give an actual genuine review.

To see the test results scroll to the end of this article.

That being said, autotune is an essential plugin in most producers arsenal, and we’ve made a list of the best free VSTs that you can download right now and have some fun with.

Here are 5 of the best free autotune VST plugins in 2019:

KeroVee

Made by a Japanese company called g200kg. KeroVee is a completely free-to-download pitch correction VST. It boasts powerful and natural pitch correction capabilities and can be set to either follow any given scale or MIDI input. The scale mode is controlled by the user enabling or disabling which notes they want KeroVee to pitch-correct to, and the MIDI mode works by taking MIDI input which holds note information and tells the plugin which notes to pitch correct to.

You can control the TuneSpeed, Nuance and Amount to achieve either a robotic Cher-like sound or a more natural sound. It also allows for formant shifting so you can change the tonality of the vocal to sound more male or female like or darker/lighter. Other functions include transpose and fine tuning, master volume, and panning.

The interface is a bit barebones, windows 98 looking but I don’t mind that at all. In fact the whole retro look has really started to grown on me lately. The UX is simple and intuitive, it does exactly what it is supposed to do and does it surprisingly well!

What I liked

Selecting the key you want to use is simple using the “scale setting”.

The visual feedback works nicely and you can see the pitch correction speed changing in the time based graph style window.

The three knobs at the top; time , nuance and amount was all I really needed to play with to achieve the desired effects so its super easy and quick to use.

and was all I really needed to play with to achieve the desired effects so its super easy and quick to use. It did a great job on really fast settings. I would probably opt for this plugin if I was going for the T-Pain effect.

What I didn’t like

Short of reading the manual, it’s not obvious what “Tone 1” and “Tone 2” control. Is it the L/R channels?

Unfortunately KeroVee is only available for Windows. No OSX versions have been made available as of the time of writing.

Download and installation instructions:

Visit https://www.g200kg.com/jp/software/kerovee.html to download the latest version.

Place the KeroVee.dll file in your hosts VST directory.

Grallion2

Not just your average pitch correction tool. Grallion 2 is made by a company called Auburn Sounds. They have 3 products, all of which offer free and paid versions. They have a pretty awesome stereo positioning tool called Panagement, and an awesome little dynamics controller/compressor/saturator/transient shaper called Couture. But that’s not what we’re here for!

Grallion 2 delivers a range of features including their proprietary Pitch-Tracking Modulation which generates throat sounds, makes octave and fifth doubles, choruses and can enrich a vocal to make it more masculine. It also features a neat little 2-knob bit crusher, a low-cut filter, transposing and formant shifting as well as a mix knob.

The interface is nice and modern and has some great visual feedback in the style of a spinning circle to indicate which note the signal is being adjusted to.

The correction settings allow you to control the speed and amount of pitch correction you want as well as the “Snap Range” which dictates how far out from the given note the signal needs to be before pitch correction kicks in. For example, if you have pitch correction enabled for the note A3, and the signal is hovering 0.5 semitones away from A3, the Snap Range would have to be set to 0.5 or higher, otherwise the signal wouldn’t be affected.

What I liked

The interface looks good and it is blatantly obvious what each of the controls does.

It has a handful of other useful features such as the pitch tracking mod which lets you create octave and fifth doubles of the sound essentially harmonizing the vocal in a synthetic manner. I also like that there is a bit crusher. Although these are only available on the paid version.

Fast settings sounded pretty good.

What I didn’t like

Not too sure on this circle style visual feedback. I prefer a time based graph style window as it’s easier to look back and see the speed and accuracy of the pitch correction.

Slow settings seemed to struggle a bit with the formants, making strange phasey artifacts at some points.

You have to click all the notes in instead of just choosing a scale. No big deal breaker but it would be a nice addition.

You have to pay to get all the features. So as a free plugin it only really offers pitch correction and shifting.

Grallion 2 comes available as VST2, VST3, AAX, and Audio Unit plug-in for Windows and macOS.

Download and installation instructions:

Visit https://www.auburnsounds.com/products/Graillon.html to download the latest version

Extract the DLL/AU and place it in your plugin folder.

GSnap

GVST is a software developer who releases free VSTs for Windows only. They aim to release simple, light-weight and efficient plugins. G Snap is their free VST pitch-correction plugin.

It really is one of the more simple and basic plugins and doesn’t offer much in the way of formant shifting or other features, but does offer some neat little MIDI modulation features like pitch bend and vibrato.

You can also set the detection frequency bands, gate and speed as well as choose to snap to selected notes or snap to MIDI input.

The interface is simple but intuitive and offers some nice visual feedback in a timeline-graph style window.

Unfortunately Gsnap is only available for Windows. No OSX versions have been made available as of the time of writing.

What I liked

Scale selection allows for quick configuration instead of having to click the notes in manually.

It offers vibrato for MIDI modulation which could be fun to play with.

Time based graph style visual feedback is always a positive for me.

What I didn’t like

Pitch correction is poor on this. It seems to struggle to decide which note to snap to which results in a vocal that’s constantly jumping between notes, even when the vocal stays on the same note. A lot of the time the vocal still sounded out of key even when visual feedback indicated it was being pitched to the correct note.

Download and installation instructions:

Visit https://www.gvst.co.uk/gsnap.htm to download the latest version.

Extract the DLL and place it in your plugin folder.

MAutoPitch

MeldaProduction is a well respected software development company that makes some amazing audio plugins. They have a whole host of awesome free plugins as well as paid ones.

MAutoPitch is a high quality, great sounding automatic pitch correction VST built for use on vocals and all other monophonic instruments and sound sources. It boasts powerful and creative features such as formant shifting and stereo imaging.

It has a nice simple user interface which can be scaled and styled and is GPU accelerated. It has some great visual feedback and metering features in the form of time graphs as well as classic meters.

A unique feature called Multiparameters allow you to control multiple parameters, kind of like a macro.

Not only can it handle mono and stereo signals but also mid/side encoding which allows for advanced stereo processing.

Automatic gain compensation allows you to easily flick through presets without your perspective being biased towards louder or quieter sounds. It also has a limiter in case you don’t have AGC enabled and your signal goes too hot out of the plugin.

Just as with other plugins it also has MIDI pitch tracking which allows you to pitch vocals to MIDI information instead of just predefined note information.

What I liked

I love the look of the interface – the knobs and colours probably look the best out of all the plugins I reviewed.

Scale setting allows for easy key selection.

It did a decent job on both fast and slow styles. So it’s probably the best all rounder in my opinion.

What I didn’t like

Not a fan of the visual feedback. I prefer the time based, graph style of KeroVee and GSnap.

The plugin is available in VST, VST3, AU and AAX interfaces on Windows & Mac, both 32-bit and 64-bit and comes with a lifetime of free updates.

Download and installation instructions:

Visit https://www.meldaproduction.com/MAutoPitch to download the latest version.

Extract the DLL and place it in your plugin folder.

Autotalent

Created by Tom Baran, Ph.D., CEO and co-founder of Lumii. Autotalent is a powerful and free pitch correction plugin built for both drastic and gentle pitch correction.

It was built to process any mono signal, be it a vocal or any other kind of monophonic instrument. You can control the speed and strength of the pitch correction and it includes controls for formant shifting, LFO depth, rate, quantization, shape, symmetry and mix controls. You can also control the master tuning away from the usual A (440Hz).

The interface is as basic as it comes and looks like a work in progress. The whole plugin seems to be slightly un-finished and has only been compiled and tested in linux. Therefore, you can only download a linux version of it. The developer states that it should in theory work on MacOS and Windows, you just need to compile it for them. I’m no developer so don’t ask me how to do that 🙂

EDIT: There is now a Windows and MacOS version made available by Oli Larkin. You can grab it here.

I included it because, it’s free and open source, and despite my test results it is more than capable of creating a great sounding vocal. Just check out the demo below!

http://tombaran.info/autotalent-0.2-demo01.mp3

What I liked

The interface is simple and barebones which I sometimes like.

If you look past the horrible distortion, Autotalent actually did a good job of pitch correcting on both fast and slow settings.

What I didn’t like

My tests resulted in some nasty distortion no matter how I configured the plugin.

The way you select notes, having to dial in each note separately takes a lot longer than the other plugins, and quickly switching between scales could be a bit of a pain.

You can get it at http://tombaran.info/autotalent.html

And the Windows/MacOS versions here.

Bonus Plugin: X42 Autotune (NON-VST)

Note: X42 is an LV2 plugin, not VST. I would have loved to have tried it but unfortunately my DAW cant load LV2 plugins. I still included it on the list with some info I found as it looks like it could be promising.

Created by X42, x42-autotune is a design based around Fons Adriansen’s zita-at1. It is a pitch correction plugin that is only really designed to correct vocals that are slightly out of tune. It’s not built to give you that Cher/T-Pain effect.

There are 3 modes; manual, MIDI, and Auto(default). With manual and Auto, pitch correction can be controlled by a fixed set of notes. With MIDI, the plugin takes your MIDI input and tries to correct to the corresponding note. These modes seem to be the standard for most autotune plugins we have reviewed.

The interface is nice and simple for the most part. There seems to be some weird routing section that really isn’t intuitive and I couldn’t find any info on it though the website, from looking at it, it seems to control audio in/out and side chain routing.

Overall it looks like a cool little plugin for gentle pitch correction but if you’re after more dramatic autotune then this isn’t the one for you.

The plugin comes in Windows 32/64bit, MacOS, Linux 32/64bit. The developer has also made the source code available via his Github repository. You can access this all via the link below.

Download and installation instructions:

Visit https://x42-plugins.com/x42/x42-autotune to download the latest version.

The Tests

To test this I grabbed an already nicely tuned vocal off splice and set it a few cents out of tune. The vocal is in A minor.

I then applied each autotune plugin and played with the settings until I had the T-Pain effect going. I did this for each plugin and bounced out the results.

Following that I did my best to create a natural sounding tuned vocal by using the slower settings on each plugin, and bounced them out to compare.

This is the original vocal, in tune (with an e-piano backing it so you have a key reference).

I then detuned the vocal until it sounded slightly flat.

Next, I applied each plugin with FAST T-Pain style settings:

KeroVee:

Grallion 2:

GSnap:

MAutoPitch:

Autotalent:

Then I applied each plugin with SLOW natural style settings:

KeroVee:

Grallion 2:

GSnap:

MAutoPitch:

Autotalent:

Here are the takeaways from my tests:

What I found was that certain plugins were good with fast unnatural tuning, while others excelled at more natural and slow tuning.

MAutoPitch was the best at giving a natural gentle tuning effect.

was the best at giving a KeroVee and MAutoPitch did the best at giving the harsh, T-Pain or Cher style robotic autotune, Grallion also did a good job.

did the best at giving the harsh, robotic autotune, also did a good job. GSnap had a hard time staying in pitch it kept bouncing around too much between notes.

Autotalent was full of artifacts and distortion, I cannot recommend using this plugin.

I found Grallion was doing something weird with the formant (I think) which was causing a weird phasey like effect on parts of the slow tuned vocal. Listen to the Grallion Slow Tuning mp3 at around 10-12 seconds to see what I mean.

Hopefully, this article helped you find what you were looking for. Ultimately you’re never going to get the same quality tuning as you would with the likes of Antares Autotune or Melodyne, but if you’re looking for a cheap alternative KeroVee, MAutoPitch or Grallion2 should do the trick!