VST3 and AU explained: which plugin format do you actually need?

If you've ever downloaded a plugin and seen a folder full of formats you didn't ask for, you already know the confusion. Here's the short version: VST3 and Audio Unit (AU) are two different plugin standards that do the same job, they just talk to different software. You almost never need to think about them beyond installing the right one.

The one-line version

• VST3 works in most DAWs on both Windows and Mac: Ableton Live, FL Studio, Cubase, Studio One, Reaper, Bitwig and more.
• AU (Audio Unit) is Apple's own format, used by Logic Pro and GarageBand, and Mac-only.

If your DAW supports both, it genuinely doesn't matter which you pick, use whichever loads faster or scans more reliably in your setup.

Do I need to install both?

No. Install the one your DAW actually uses. If you use more than one DAW on the same Mac, for example Logic and Ableton, it's fine to have both AU and VST3 installed side by side; they don't conflict, and most installers just tick both boxes automatically. You're not paying twice or using up two licences; it's the same plugin in two wrappers.

What about AAX and Pro Tools?

AAX is Avid's own format for Pro Tools, and it's a separate certification process from VST3 or AU, not just a different file extension.

So which do you need?

Check the table above for your DAW. If it lists both, it doesn't matter which you pick. If you're not sure what your DAW installed, most plugin scanners show the format next to the plugin name in your effects list, so you can check after the fact rather than guessing beforehand.

Try it yourself

Liminal installs as both AU and VST3 for macOS and Windows (VST3 only on Windows, since AU is Mac-only), so whichever your DAW uses, it'll show up. There's a 7-day free trial if you want to check compatibility before buying.