Audio Plugin Formats Compared (VST, VST3, AU, AAX, CLAP, LV2)
The audio plugin formats a developer might target — who made each, when, how it's licensed, and which hosts use it. If you're building plugins in code (e.g. with JUCE or Faust), this is the target matrix.
| Format | Created by | Since | License | Platforms | Used by |
|---|---|---|---|---|---|
| VSTVirtual Studio Technology | Steinberg | 1996 | Proprietary (free SDK) | macOS, Windows | Most DAWs (legacy VST2 now deprecated) |
| VST3Virtual Studio Technology 3 | Steinberg | 2008 | Proprietary (GPLv3 or paid SDK) | macOS, Windows, Linux | The current cross-DAW standard |
| AUAudio Units | Apple | 2002 | Proprietary (part of macOS/iOS) | macOS, iOS | Logic Pro, GarageBand, most macOS DAWs |
| AAXAvid Audio eXtension | Avid | 2011 | Proprietary (NDA SDK) | macOS, Windows | Pro Tools only |
| CLAPCLever Audio Plug-in | u-he & Bitwig | 2022 | Open source (MIT) | macOS, Windows, Linux | Bitwig, Reaper, and a growing list |
| LV2LADSPA Version 2 | Open community | 2011 | Open source (ISC/permissive) | Linux (some macOS/Windows) | Ardour, Qtractor, Linux hosts |
| RTASReal-Time AudioSuite | Digidesign/Avid | 1990s | Proprietary (legacy) | macOS, Windows | Old Pro Tools (superseded by AAX) |
How to read this
Plugin formats are the interface between a processor and a host. Which you need is decided by your DAW and your platform, not by preference.
VST3 cross-platform, the current standard
VST2 legacy, no longer licensed to new developers
AU Apple only — Logic and GarageBand require it
AAX Pro Tools only
CLAP newer open standard, growing support
LV2 open, common on LinuxNotes & gotchas
- The host decides. Logic will not load VST2 or VST3 at all; Pro Tools needs AAX. Check before buying.
- VST2 is legacy but everywhere. Steinberg stopped licensing it, so new plugins ship VST3 — old projects still depend on it.
- CLAP is the interesting newcomer — open, no licensing restrictions, better polyphonic modulation. Adoption is growing but not universal.
- Install paths matter. Most "plugin not showing up" problems are a scan path issue, not a broken plugin.
- Architecture must match. A 32-bit plugin will not load in a 64-bit host without a bridge, and Apple Silicon adds native versus Rosetta to the same problem.