StemMaster vs LANDR and eMastered
These are different kinds of tool, not better and worse versions of the same one. LANDR and eMastered are cloud services you upload to. StemMaster is a desktop app that mixes your multitrack and then masters it, without your audio leaving the machine.
The comparison people usually expect — “they only do stereo files, we do stems” — isn’t true, and we’d rather say so. Both LANDR and eMastered offer stem mastering. The real differences are elsewhere.
| StemMaster | LANDR | eMastered | |
|---|---|---|---|
| Where it runs | On your machine, not the cloud | Cloud — you upload, they process | Cloud — you upload, they process |
| What it takes in | Your full multitrack — dozens of individual stems | Stereo mixdown, or a handful of submix stems | Stereo mixdown, or a handful of submix stems |
| What it does | Mixes first — levels, pans, per-track automation, vocal riding — then masters | Masters: EQ, compression, imaging, loudness | Masters: EQ, compression, imaging, loudness |
| Shows its reasoning | Yes — every move explained in plain language, and overridable | No | No |
| Pricing model | One-time purchase | Subscription | Subscription |
| Your audio | Never leaves your machine | Uploaded to their servers | Uploaded to their servers |
| Works offline | Built-in engine, yes† | No | No |
| Platform | Windows 10/11 · macOS 15+ (Apple Silicon) | Any browser | Any browser |
† StemMaster ships with two engines. The built-in analysis engine is the default, needs no key and no internet, and is what the free demo runs on. The optional AI engine is opt-in, uses your own API key (Anthropic, OpenAI, z.ai and other compatible providers) and therefore needs a connection — it sends measurements taken from your stems, never the audio itself. Licence activation contacts Polar once, then revalidates every 30 days.
Competitor plans and features change often, and we don’t quote their prices here because any figure we printed would be out of date before you read it. Check landr.com and emastered.com for current terms.
The difference that actually matters
Stem mastering balances a few submix stems and then masters the result. That is a mastering job with extra control.
StemMaster starts a step earlier. It loads every track you bounced — twenty or thirty of them, not four — and makes mixing decisions: what sits where, what ducks under what, which sections need the vocal pushed. Then it masters what it built. If your mix is already finished and you just need it loud and balanced, that extra stage is work you don’t need. If your mix isn’t finished, it’s the whole point.
And it tells you why
Every AI mastering tool makes decisions. StemMaster is the one that writes them down: which track it pulled back and by how much, where it rode the vocal, what it did to the low end and on what evidence. You can disagree with any of it — move a fader and the master re-renders around your change, loudness-matched so the A/B is fair.
That matters less if you want a finished file and no opinions. It matters a lot if you’re trying to get better at mixing, because a black box that hands back a louder file teaches you nothing.
When something else is the better choice
Genuinely, and we’d rather you know now than ask for a refund later:
- Your Mac is an older one. StemMaster runs on Windows and on macOS, and one purchase covers both, sharing the same 3 activations — but the Mac build needs Apple Silicon (M1 or later) on macOS 15 or newer. Intel Macs are not supported, and neither is an older macOS, so check that before you buy. There are desktop tools that do run on an Intel Mac, so it is worth looking before you assume uploading is all that is left.
- You work from a phone or a tablet. There is no desktop app for either — ours or anyone else’s. LANDR and eMastered run in a browser on anything, and that is the whole answer here.
- You only have a finished stereo bounce. No stems, no multitrack — then there’s nothing for StemMaster to mix, and a stereo masterer is exactly the right tool.
- You master a track or two a year. A one-time purchase only beats a subscription if you actually keep using it.
- You want distribution bundled in. LANDR sells mastering as part of a wider release platform. We sell one desktop app and nothing else.
Try it before you decide
The demo is the full application with exports disabled and a periodic tag on mastered playback — enough to load your own stems and hear whether the mix is any good on your material. If you buy and it isn’t for you, there’s a 14-day refund, no questions.
Windows SmartScreen may show a notice on first install (we’re a new publisher) — click More info → Run anyway.