Online Mastering Services: Reviewing the Top 11 Services in 2021 (Including Audio Samples)
Whether you’re new to recording or a seasoned veteran, it’s likely you’ve come across online mastering services such as Landr, Emastered, Bandlab, Cloudbounce and more.
These platforms use an algorithm to master tracks – meaning your music will typically not be heard by human ears – instead, your track is run through some software that automatically makes adjustments to volume, compression and EQ based on a formula the algorithm applies.
So are these services any good? Do you really need a mastering engineer or can a computer handle your track?
Well to find out, I tested out 11 of the best algorithm-based online mastering services to bring you an honest look at what you may be able to get for yourself – and when it’s worth trying one of these services versus going with a mastering engineer.
For this exercise I uploaded the exact same song to all services. The song is called Cynical and it was produced and mixed by Caleb Owen. I chose this mix because it’s well balanced and didn’t have any overall problems.
For comparison purposes I have created two versions of the same files, the original as received/downloaded from the AI mastering services and one that is level matched with the original mix at -14LUFS. I’ve done the level match so we don’t get deceived by loudness (it’s a proven fact that a louder song always sounds better than a quiet version of the same).
Files have been converted to MP3 to avoid web speed issues. For the purposes of this test, I left all the AI mastering settings at its default setting.
Hope you find it useful. If you have any questions, please get in touch and I’d be happy to help. If you’d like to see how your track sounds and compares to an algorithm-based service, request your free mastering sample here.
1. Landr
Launched in 2014, Landr is a creative platform that provides AI powered mastering, distribution, plugins and promotion packs.
It was very simple to create an account and upload your track. Once you started mastering, the mastering process itself was fast, only taking about 2 to 3 minutes. Once the track was mastered you could also easily preview the mastered track and compare it with the original, however, this was only available for a snippet of the track – not the whole track.

Another pro is that there were quite a few options available to customise and tailor the mastering. For instance, you could change the master’s style (warm, balanced, open), as well as intensity (low, medium, high). You also could upload a reference track. For the purposes of this test, I left everything to its default setting.

This is a big plus for Landr, as at the time of writing it’s one of the only services that allows for album mastering i.e. it checks for consistency between tracks. We didn’t test this out, as we just did one track, but it’s good to know it has this feature.
Landr was not as cheap as some of the other AI online mastering services. If you’re just looking for a very quick and dirty master at low res (Lo-MP3) the basic plan is quite affordable. However, if you’re looking for higher quality files (HD WAV which is necessary for many streaming sites), Landr isn’t that much cheaper than going to a professional mastering engineer (assuming you produce/release one track a month). And it’s without the support and opportunity for revision, personalisation and mix feedback that you’d get from working with a professional mastering engineer.
Also, if you need different versions of the same track, you need to pay extra for each file which hikes up the cost. Compare this to a mastering engineer, where you’d get HD WAV files and mp3s as part of standard deliverables. Here’s a summary of their payment options (as at December 2020):

Landr allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Landr:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
2. emastered
Similar to Landr, emastered is one of the major algorithm based online mastering services out there. It was founded by Grammy Winning Co Founder Smith Carlson.
It was very simple to upload the track – no sign up needed to get started.


Another pro is that there were quite a few options available to customise the mastering including: compressor intensity, mastering strength, stereo width, volume, equalisation. These settings can be saved as presets – good option if you’re mastering several tracks through the platform.

Unlike Landr, there was no extra cost to download HD WAVs.
Very affordable service, particularly if you have several tracks you would like to master, as they offer unlimited masters.

Need to sign up to a plan to use the service. However, they do offer a 14-day money-back guarantee in case you change your mind.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
eMastered allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with eMastered:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
3. bandlab
BandLab is a social music platform that in 2016 added a free automated online mastering service.
It was very simple to upload the track – no sign up needed to get started. Once you started mastering, the mastering process itself was very fast, only taking about 20 seconds.

Though there were slightly less options for customisation compared to eMastered, BandLab still offered some settings you could choose depending on your preferences. This included: CD Quality, Bass Boost and Enhance Clarity. Once the track was mastered you could also easily preview the mastered track and compare it with the original. Unlike Landr, you can listen to your whole track, not just a snippet.

Band lab is completely free. This is quite good if you just want to test out the service with no commitment and see what mastering could do for your track.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
BandLab allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with BandLab:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
4. cloudbounce
Since 2016, CloudBounce, based out of Finland and the UK, has provided instant online mastering services.
Similar to other services, it was very simple to upload the track – no sign up needed to get started. It only took 2-3 minutes in total to master the track. Once the track was mastered you could also easily preview the mastered track and compare it with the original. Unlike Landr, you can listen to your whole track, not just a snippet.

Lots of options to customise the master based on genre.

CloudBounce is definitely affordable, with plans available from just $19.90 per month. This is a good option if you have lots of tracks you plan on releasing regularly. Another bonus is that you can buy tracks one-off for $9.95 per track.

If you buy a track one off, you only have 7 days to download the track, otherwise it’ll be deleted. This likely won’t be an issue for most people, but something to keep in mind.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
CloudBounce allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with CloudBounce:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
5. chosen masters
Based out of Vancouver, Chosen Masters describes itself as a semi-automated, professional grade online audio mastering tool that adds colour, warmth and brilliance to your tracks.
Similar to other services, it was very simple to upload the track – no sign up needed to get started. You can even upload your track directly from Dropbox. Very fast service – only took 2-4 minutes in total to master the track. They also have a user tutorial which takes you through all the features.

Very similar pricing to CloudBounce and definitely affordable, with plans available from just $19.90 per month. This is a good option if you have lots of tracks you plan on releasing regularly. Another bonus is that you can buy tracks one-off for $9.99 per track.

There were slightly less options to customise the master based on your preferences, but still some options available including: dynamic, balanced and powerful.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Although Chosen Masters flags in their tutorial that they recommend 32 bit WAV uploads, they still don’t stop you from uploading mp3s!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Chosen Masters:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
6. Major Decibel
Major Decibel is an independently owned and operated automated online mastering service that launched its Mastering Engine 2.0 in 2018.
Similar to other services, it was very simple to upload the track – no sign up needed to get started. Very fast service – only took 3-4 minutes in total to master the track.

This is one of the most affordable platforms – you can get two tracks for free per month and a yearly subscription for just $25. However, it’s worth noting you can only download MP3s with the free account.

Though there are less options to customise than other mastering platforms, you can still choose between low, medium and high mastering intensity. There is also a before/after player to allow you to compare the results.

Unlike Landr, there’s currently no option for mastering an album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Although Major Decibel recommends you upload your track in WAV format, they still don’t stop you from uploading mp3s!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Major Decibel:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
7. aria
Aria Mastering is an automated analog online mastering service that was built by mastering engineer, Colin Leonard.
It took about 2 minutes to upload the track and another 5 minutes for the mastering process, which was a little slower than the other platforms we tried.
Aria Mastering provided a lot of options for customising the track. When uploading the track you can choose the mix type, and customise settings such as low frequency, high frequency, width and output level. You can also choose a specific LUFS when exporting the track (at extra cost).


Compared to other services, there were more steps to get started i.e. you need to register an account, confirm email, and log into the account before you can start mastering.
Unfortunately, you can only preview for free 15 seconds of the mastered track.

Out of all the options we compared, Aria Mastering was the most expensive service. There was also an extra fee for downloading high quality files.

Unlike Landr, there’s currently no option for mastering an album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Aria Mastering allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Aria Mastering:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
8. maztr
Established in 2016, Maztr was set up by a group of audio engineers and musicians who saw the need to help the home recording artist master songs and podcasts in the cloud.
Similar to other services, it was very simple to upload the track – no sign up needed to get started. Very fast service – only took 2 minutes in total to master the track.
Out of all platforms, Maztr provided the most choice for customisation. You can make minor adjustments based on the below:

or you can use the advanced customisation which allows you to tweak the below settings:

Maztr offer a free plan, allowing you to master unlimited tracks for free! However, you can only download low-res tracks ($4.99 for each HDWAV track). Paid plans which include high res formats are very affordable, starting at $9.99 per month.

Maztr don’t offer a before/after player allowing you to compare the mastered version versus the original.
Unlike Landr, there’s currently no option for mastering an album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Maztr allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Maztr:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
9. mastering box
Though there are less options to customise than other mastering platforms, you can still customise the loudness and EQ. There is also a before/after player to allow you to compare the results.

It took only 2 minutes to master in total. One of the fastest services – only taking two minutes to master in total.
Mastering Box offers free masters (you can only download MP3s though). Otherwise, you can purchase WAVs and HD WAVs for a one off price, as well as subscribe to a regular service. Pricing in line with similar services.


Compared to other services, there were more steps to get started i.e. you need to register an account, confirm email, and log into the account before you can start mastering.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Mastering Box allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Mastering Box:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
10. schnalz
Established in 2019, Schnalz is an online mastering service that was created by a dedicated team of music enthusiasts.
Though there are less options to customise than other mastering platforms, you can still customise the intensity, and settings such as bass, treble and width.

Scnalz allows you to try two different masters and compare the difference. This is a great feature for determining what settings work best for your track.

Schnalz is completely free. This is quite good if you just want to test out the service with no commitment and see what mastering could do for your track. You also have the option to make a donation.

Compared to other platforms, Schnalz was the slowest – taking us 8 minutes just to upload the track.
Compared to other services, there were more steps to get started i.e. you need to register an account, confirm email, and log into the account before you can start mastering.
Unlike Landr, there’s currently no option for mastering a album. This is a big drawback if you have an EP or album that needs mastering, as you need to ensure consistency between tracks.
Schnalz allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with Schnalz:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
11. soundcloud
Powered by Dolby, Soundcloud’s online mastering service allows you to master your track directly within SoundCloud’s platform.
Though there are less options to customise than other mastering platforms, you can still customise the intensity, and choose between four different mastering styles Thunder, Sunroof, Aurora and Clear Sky. For the purposes of this test, we chose Sunroof.

This is a big plus for SoundCloud, as at the time of writing it’s one of the only services that allows for album mastering i.e. it checks for consistency between tracks. We didn’t test this out, as we just did one track, but it’s good to know it has this feature.
To get access to the mastering service, you need to sign up to Pro Unlimited which is around $10 per month. As part of this, you get 3 free masters and $3.99 per master thereafter.
At the time of writing, there’s no way to try the mastering service without signing up to SoundCloud’s platform overall.
SoundCloud allows you to upload an mp3 when mastering your track, even though this is something definitely not recommended due to lower quality. It’s surprising that there are no warning signs or notifications telling you not to do that!
There is no option to listen to a level matched track before and after mastering. This is very important to hear the exact changes happening during mastering and if the song sounds better or not! Without level matched comparison more often than not the louder version will always be perceived as better sounding, but this might not be the case.
Here’s how the track turned out with SoundCloud:
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
Final verdict
Algorithm-based online mastering services may have some drawbacks, but when you’re pressed for time, they often can’t be beaten. This is because many algorithm-based mastering services can process tracks within minutes since there isn’t an in-depth review involved.
Algorithm-based mastering can also come in handy when you simply want to get a glimpse at the potential for your track or when you want to check a mix against standardized processing. You may have a quick demo mix that you think sounds good, and perhaps you just want to add some overall compression and limiting to get that “radio sound” through a volume boost.
Basically, algorithm-based online mastering services are often the go-to choice for musicians who want a preview of how good their tracks can sound in the mastering process. These services are often a good stepping stone on the musical journey between a rough mix and a radio-ready track.
In most cases, you’ll want to work with a mastering engineer when you need to ensure that your music will be treated with personal attention. Working directly with a mastering engineer gives you the chance to set expectations regarding what you want to get out of the final result, and your engineer can make changes based on these expectations.
A mastering engineer can also make specific adjustments after the fact. This is a benefit that often isn’t available through algorithm-based online mastering services simply because no actual human is listening. Working with a mastering engineer gives you more control over the final product, and this can go a long way in allowing you to have more freedom to express your art.
When deciding on whether to work with a mastering engineer or go with an algorithm-based service, it really comes down to how much control you want to have over your own music. An algorithm-based online mastering service may be faster and less expensive, but these services do tend to work by applying a rubber stamp to each track because no one is actually listening.
When you partner with a professional mastering engineer, you’ll receive the personal attention your music deserves, as well as the experience and specialized equipment that come along with a mastering engineer’s touch. Additionally, a mastering engineer will be far more likely to be able to offer the ability to make changes to a master after the first pass, giving you more freedom in getting the sound you’re after.
I hope you found the reviews useful. If you have any questions, please get in touch, and I’d be happy to help. If you’d like to see how your track sounds and compares to an algorithm-based service, request your free mastering sample here.
P.S. here’s the final master Caleb and I worked on. If you enjoyed Caleb’s music, you can listen and buy his EP on Apple Music here.
ORIGINAL MIX & MASTER
MIX & MASTER level matched at -14LUFS
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