What Is AUv3?

AUv3 — short for Audio Units version 3 — is Apple’s plugin format for iOS and iPadOS. If you want to run a third-party synthesizer or effect inside GarageBand on your iPad, use a multi-synth host like AUM or BeatMaker 3, or stack instruments inside Logic Pro for iPad, AUv3 is the mechanism that makes it work. There is no alternative that runs natively on iPhone or iPad. If you’re building a mobile music production setup, understanding AUv3 is non-negotiable.

The Difference Between AUv3 and Desktop AU

Audio Units (AU) is a plugin format Apple created for macOS. You see it on every Mac DAW: Logic, GarageBand for Mac, Ableton Live, and so on. AUv3 is the iOS successor — it shares the name and some conceptual DNA, but it’s architecturally different.

The critical distinction is sandboxing. On macOS, a plugin runs in the same process space as the DAW. On iOS, every AUv3 plugin runs in its own sandboxed process. The host app and the plugin communicate but are isolated from each other. This is why AUv3 is more stable on iOS than older plugin architectures were on desktop — a crashing plugin can’t take the host down with it.

Desktop AU plugins do not run on iOS. iOS AUv3 plugins do not run on macOS. They are separate formats that happen to share a naming heritage.

Why AUv3 Matters for Mobile Production

Before AUv3, iOS music production meant using standalone apps that couldn’t talk to each other in real time. You could record from a standalone synth app into GarageBand by bouncing audio, but you couldn’t play a third-party synth live inside a DAW session the way desktop producers do every day.

AUv3 changed that. When a developer ships an AUv3 plugin, it becomes available as a loadable instrument or effect inside any compatible host. You can run Moog Model D, Korg Wavestation, and Arturia iSEM simultaneously inside AUM, with MIDI routing between them and effects chains on each. That’s a legitimate production workflow, all happening on a device that fits in your pocket.

The practical implication: if you’re evaluating iOS synths or effects, an app that ships as AUv3 is significantly more useful than one that only runs standalone. Standalone-only apps are stuck in silos. AUv3 apps integrate into your workflow.

Hosts That Support AUv3

Not every iOS audio app is an AUv3 host. Some apps are purely standalone. The following apps are the primary AUv3 hosts that producers actually use:

GarageBand ships free on every iPhone and iPad. AUv3 instruments and effects appear in its plugin browser once installed. Routing is simple — one track, one instrument — but it’s the easiest entry point.

AUM (Audio Mixer) is the power user’s choice. Every channel can host AUv3 plugins, and MIDI routing between plugins is fully configurable. If you want complex signal flow on iOS, AUM is the tool.

Audiobus 3 predates AUv3 and still works. Many producers who started before AUv3 exist still prefer its routing model. It supports AUv3 alongside its original inter-app audio framework.

Cubasis 3 (Steinberg) is the closest thing to a desktop DAW on iOS — timeline-based arrangement, MIDI editors, full project management, and solid AUv3 support.

BeatMaker 3 (Intua) is built around pads and patterns and is popular with beat producers who want an iOS-native workflow.

Logic Pro for iPad is Apple’s own pro DAW, rebuilt for iPad, with full AUv3 support alongside its native instruments and effects.

How to Use an AUv3 Plugin

The workflow is straightforward once you understand it:

1. Download the app from the App Store and open it once in standalone mode to complete any initial setup (authorization, sample downloads, preset initialization). Some AUv3 plugins require this first-launch step before they register with the host.

2. Open your host app (GarageBand, AUM, etc.) and add a new instrument or effect track.

3. In the plugin browser or effect chain section, look for an “Audio Units” or “AUv3” category. The installed plugin will appear there, not as a standalone app.

4. Load the plugin. It renders inside the host’s interface as a dedicated panel or opens in a separate view. You can switch between the host and the plugin view without interrupting audio.

5. MIDI and audio pass through the host’s routing. The plugin responds to the host’s tempo, can receive MIDI from keyboards or sequencers, and its output flows through the host’s mixer.

Common Points of Confusion

AUv3 mode is not the same as standalone mode. Opening an AUv3-capable app from your home screen runs it standalone. Loading it inside GarageBand or AUM runs it as a plugin. The audio engine is the same but the routing and context differ entirely.

Not all iOS audio apps are AUv3-compatible. A standalone-only app cannot be loaded into a host. When evaluating a plugin, check explicitly for AUv3 support.

AUv3 is not Inter-App Audio. Apple deprecated IAA in iOS 13. AUv3 is the current standard — most modern apps have dropped IAA entirely.

iPadOS and iOS AUv3 plugins are usually the same binary. Developers ship universal apps for both platforms. The plugin behaves identically on iPhone and iPad.

Prioritize AUv3-capable apps when building an iOS production rig. The ability to route, stack, and sequence multiple plugins inside a single host is the difference between a toy setup and a real workflow.