Best-of guide — By WATMM Desk —
Best AI mastering services in 2026 (desk review): eMastered, iZotope Ozone, LANDR and Masterchannel
A desk review of four AI mastering options from what their makers publish, with no scores yet. Prices and features are easy to compare. The real differences are in the terms, from eMastered's clause letting it train on uploads, to LANDR's opt-in training programme, to Ozone, which runs in your DAW and needs no upload at all.
Key facts
- LANDR charges $10 to master a single track, outputs MP3 (320 kbps), 16-bit WAV and 24-bit HD WAV, and its terms say AI training on recordings runs through an opt-in Fair Trade AI Program for LANDR Distribution users.
- iZotope Ozone 12 is a plug-in (AAX, AU, VST3); every edition's Master Assistant has a Custom flow with a LUFS target, Advanced is $499, and the iZotope Plus subscription ($15 a month) includes Ozone 12 Standard.
- eMastered's FAQ says you own what you upload, but its terms say it may use uploaded content to help improve, train and develop its technologies, including AI and machine learning.
- Masterchannel's plans start at $15 a month billed yearly; its terms limit its use of your files to providing and supporting the service, and say files are deleted about six months after upload.
This is a desk review, not a test. We compared what each maker publishes on its own pricing, product, help and terms pages, linked every page we used, and gave no scores. Payment plays no part in which tools appear or in what order; they're listed alphabetically. Scores come after hands-on testing (see how we test and rank).
We left out services whose pages we couldn't open from our system, and we only report prices a maker publishes itself.
How do they compare?
| Where it runs | Published price | Formats (as published) | Loudness control | Your rights and training (as published) | |
|---|---|---|---|---|---|
| eMastered | Web | We couldn't read prices on its pages | In: AIFF, WAV, MP3 up to 900 MB | Not stated on the pages we read | You own uploads; terms allow training on uploaded content |
| iZotope Ozone 12 | Plug-in in your DAW (AAX, AU, VST3) | Advanced $499; in iZotope Plus ($15 a month) and Pro ($25 a month) | Whatever your DAW exports | LUFS target in Master Assistant's Custom flow | No upload; the product page says nothing about data |
| LANDR | Web, plus a plug-in | $10 per track, or a LANDR Studio plan | In: WAV, AIFF, FLAC, MP3. Out: MP3 320, 16-bit WAV, 24-bit HD WAV | Styles that vary in intensity and loudness | "Your Assets are yours"; training is an opt-in programme for LANDR Distribution users |
| Masterchannel | Web | From $15 a month, billed $180 a year | Not listed on its pricing page | Loudness analysis and metering | Files "remain 100% yours"; limited uses; deleted after about six months |
"Not stated" means the page we read doesn't say. It doesn't mean the feature is missing.
eMastered
eMastered describes itself as an online engine "made by Grammy-winning engineers, powered by AI", and its home page offers to master an upload for free. Its FAQ lists AIFF, WAV and MP3 files up to 900 MB, and answers the ownership question plainly: "you own what you upload, we don't own any of it." Its pricing page didn't show prices to our tools, so we haven't listed any.
The catch is in the terms of service. In the privacy section, you "acknowledge and agree" that eMastered may use uploaded content and related data to help improve, train and develop its technologies, including those involving AI or machine learning. We found no opt-out described there. Owning your track and letting a company train on it aren't contradictory. But the FAQ only tells you the first half.
iZotope Ozone 12
Ozone is a plug-in suite for AAX, AU and VST3 hosts, not an upload service. Its Master Assistant builds a starting chain you then adjust, and the new Custom flow lets you pick a genre profile, add reference tracks, set a LUFS target and choose processing strength. iZotope's comparison shows the Custom flow in all three editions: Elements, Standard and Advanced.
Advanced is $499 on iZotope's site. Through a subscription, iZotope Plus ($15 a month or $150 a year) includes Ozone 12 Standard, and iZotope Pro ($25 a month or $250 a year) includes Advanced. The trade-off, on paper, is effort: as a full plug-in suite Ozone should give you the most control of the four, and it's the one that most expects you to know what you're doing with it. Testing will tell.
LANDR
LANDR's mastering page prices a single master at $10, with unlimited free previews; you pay to download. It takes WAV, AIFF, FLAC or MP3, and returns MP3 at 320 kbps, 16-bit WAV or 24-bit HD WAV. Every LANDR Studio plan includes MP3 masters, and Standard and Pro add the WAV formats. You choose from styles "varying in intensity and loudness", and you can upload a reference track. The page gives no LUFS figures.
LANDR's terms say "Your Assets are yours", and give LANDR only the limited rights it needs to run the service. Training on recordings is set out in a separate Fair Trade AI Program, open to LANDR Distribution users who opt in. It pays a pro-rata share of 25% of net revenue from AI products built on the data. To join, you must own 100% of the master and publishing rights and waive moral rights. And if LANDR licenses a dataset on a perpetual basis, your recordings stay with that licensee for good; opting out applies to future licences only. The terms don't say explicitly whether files uploaded only for mastering can feed LANDR's own engine. A broader clause lets it use "Your Data", as defined in its privacy policy, to improve its services.
Masterchannel
Masterchannel lets you shape your sound with "the profile" of the engineers Simon Hestermann and Wez Clarke. You can steer it by genre and mood, and it promises to help you "hit your loudness targets" with loudness analysis and metering. Billed yearly, plans are Artist at $15 a month ($180 a year), Professional at $19 a month ($228 a year), which adds a Wez Clarke profile and post-master tweaks, and Partner at $79 a month ($948 a year). Its pricing page doesn't list output formats.
Its terms, updated on 12 October 2026, are the narrowest of the three upload services. Uploads "remain 100% yours". Masterchannel may access and process them only to provide the service, handle support, monitor service quality and fix technical issues. It "does not claim any other ownership or usage rights", and files are deleted automatically about six months after upload.
What we'll test, and how we'll score it
Our methodology page says only hands-on tests carry scores. When we test these four, we'll score each on its scoring rubric, using all five criteria and the published weights:
- Performance (35). Blind A/B listening on the same mixes across genres, with every master level-matched first so the loudest doesn't win by default. Plus loudness accuracy: measured integrated LUFS and true peak against the target each tool claims or lets you set.
- Rights and data (20). Who owns the master, what the terms let the company do with your upload, and how long it keeps it.
- Cost and limits (20). Cost per finished master, for one single, an EP and a year of releases.
- Workflow and formats (15). Input and output formats, stems, album consistency and turnaround.
- Control (10). What you can change after the first pass, and whether the changes do what they say.
What we think
On sound, these services may turn out closer than their marketing suggests. On terms, they're already far apart, and that matters more than it first looks. A mastering upload is a finished and usually unreleased version of your track, the most valuable file you have. eMastered's terms let it train on that file, and its FAQ doesn't mention it. LANDR keeps training to an opt-in deal, with a real catch on perpetual licences. Masterchannel limits what it may do with your file and deletes it. Ozone never takes the file at all.
Loudness is the other place to stay calm. Spotify normalizes playback to -14 LUFS at its Normal setting (Premium listeners can choose other levels), so a louder master is simply turned down. A service that lets you set or see a target is worth more than one that only promises "loud".
Our advice for now: read the terms before you upload anything unreleased, especially a client's track. If a service's FAQ and its terms tell different stories, believe the terms.
Sources
- eMastered online mastering, eMastered (primary source). Accessed 23 Oct 2026.
- eMastered pricing, eMastered (primary source). Accessed 23 Oct 2026.
- eMastered FAQ, eMastered (primary source). Accessed 23 Oct 2026.
- eMastered Terms of Service, eMastered (primary source). Accessed 23 Oct 2026.
- Ozone 12 mastering, iZotope (primary source). Accessed 23 Oct 2026.
- Ozone 12 edition comparison, iZotope (primary source). Accessed 23 Oct 2026.
- iZotope subscriptions, iZotope (primary source). Accessed 23 Oct 2026.
- Online audio mastering, LANDR (primary source). Accessed 23 Oct 2026.
- LANDR Terms of Service, LANDR (primary source). Accessed 23 Oct 2026.
- Masterchannel pricing, Masterchannel (primary source). Accessed 23 Oct 2026.
- Masterchannel home page, Masterchannel (primary source). Accessed 23 Oct 2026.
- Masterchannel Terms of Service, Masterchannel (primary source). Accessed 23 Oct 2026.
- Loudness normalization, Spotify for Artists (primary source). Accessed 23 Oct 2026.
Researched with AI assistance, written and checked by WATMM Desk.