OBS's built-in VST filter still does not support VST3. Modern studio plug-ins increasingly ship as VST3-only. OBS Safe VST3 Host closes that gap with a native OBS filter and crash-isolated VST3 hosting for Windows.
Public stable: v0.5.0 · Native OBS VST3 audio-effect workflow · Isolated host process · Real vendor GUI · Automatic discovery · State recovery
Product website: https://masarray.github.io/obs-vst3/
OBS Studio's official VST documentation currently lists VST3.x as unsupported by the built-in VST filter and warns that some VST plug-ins can crash OBS, recommending users save or back up settings when experimenting: https://obsproject.com/kb/vst-2-x-plugin-filter
That creates a growing gap for streamers, creators and broadcast engineers: many modern EQs, compressors, restoration tools, reverbs, saturators, limiters and mastering processors are now distributed primarily—or only—as VST3.
OBS Safe VST3 Host is designed to make those tools practical in OBS.
- VST3 audio effects inside the normal OBS Filters workflow.
- Broad compatibility with popular studio VST3 effects, without a vendor-name whitelist.
- The real vendor plug-in GUI brought to the foreground for immediate tweaking.
- Crash-isolated runtime: third-party VST3 DSP and GUI code run outside
obs64.exe. - Crash-isolated scanning: plug-in discovery also probes candidates outside OBS.
- Dry fail-open audio: an unhealthy wet path is not allowed to intentionally block the OBS realtime callback.
- State persistence and recovery: component/controller state can be restored after helper recreation.
- A simple Windows installer plus a portable/manual package.
The result is a practical path to using the same class of studio processing you use in a DAW while livestreaming in OBS.
Download the latest stable release and choose:
OBS-Safe-VST3-Host-v0.5.0-Setup-x64.exe
Close OBS, run the installer, select your OBS folder, then start OBS again.
Portable/manual package:
OBS-Safe-VST3-Host-v0.5.0-Windows-x64-Portable.zip
Every release also includes SHA256SUMS.txt.
Beginner guides: Install on Windows · VST3 compatibility · Crash-isolation safety model · Product roadmap
OBS Safe VST3 Host does not try to invent a new sound engine or replace the plug-ins you already trust. It gives OBS access to modern VST3 audio effects so you can build a live signal path with tools such as:
- corrective and dynamic EQ;
- compression, expansion and de-essing;
- noise reduction and restoration;
- saturation, coloration and harmonic processing;
- reverb, delay and spatial effects;
- limiting, maximization and mastering-style finishing processors.
That means a livestream can use studio/mastering-grade processing tools instead of being limited to the older VST formats available in OBS's built-in filter. Final audio quality still depends on the source, the plug-ins and how they are configured—the host's job is to make those tools usable and reliable inside the live workflow.
A VST3 plug-in is native code. Loading third-party native code directly into the broadcast process creates an obvious failure boundary: if the plug-in fails badly, the host process can fail with it.
OBS Safe VST3 Host changes that boundary:
OBS Studio (obs64.exe)
│
│ bounded audio/control IPC
▼
obs-safe-vst3-host.exe ← isolated helper process
│
├── VST3 DSP
├── native vendor GUI
├── state persistence
└── watchdog / recovery
│
▼
third-party VST3 audio effect
The third-party VST3 module and vendor interface run in the helper process, not inside obs64.exe. If the helper or plug-in becomes unhealthy, the filter is designed around bounded failure handling, dry fail-open audio and helper recovery instead of intentionally blocking OBS's realtime audio path.
This materially reduces the risk of a plug-in failure taking down OBS together with unsaved session changes. It is still not a mathematical guarantee that OBS can never crash: drivers, the operating system, hardware failures, OBS itself and malicious native code remain outside this project's control.
- In OBS, open an audio source → Filters.
- Press + and add VST 3.x Plug-in.
- Under 1. Plug-in Source, keep Installed plug-ins or browse to a
.vst3file. - Choose the effect under 2. Installed Plug-in.
- Click 3. Open Plug-in Interface.
- Tweak the real vendor GUI. It opens in front of OBS so you can work immediately.
Installed effects are discovered automatically. Use Refresh Plug-in List after installing a new VST3 while OBS is already running.
v0.5.0 targets conventional Windows x64 VST3 audio effects in the current mono/stereo Float32 host scope. It is not tied to a vendor whitelist.
Real-machine qualification has included popular commercial effects such as:
- iZotope — Ozone 11, RX 9 Spectral De-noise
- FabFilter — Pro-Q 3, Pro-C 2, Pro-R, Saturn
- Waves — SSL Channel
- Klevgrand — Brusfri
- Neuro Audio — Westwood
- Process Audio — Sugar
The scanner uses VST3 metadata conservatively: normal effects remain eligible, while plug-ins that explicitly identify as instrument-only are excluded from the OBS insert-effect list.
This gives the host broad compatibility across the kinds of VST3 effects commonly used in studio and mastering workflows, while keeping the current product scope honest. See the live compatibility page for details.
| Capability | v0.5.0 |
|---|---|
| Windows x64 | ✅ Supported |
| OBS Studio 29.1+ | ✅ Supported compatibility floor |
| VST3 audio effects | ✅ Supported |
| Installed plug-in discovery | ✅ |
| Native vendor editor | ✅ |
| Foreground editor workflow | ✅ |
| Mono / stereo Float32 | ✅ |
| Full VST3 state persistence | ✅ |
Crash/hang isolation from obs64.exe |
✅ Architectural boundary |
| Instrument-only VST3 / MIDI | 🚧 Roadmap |
| Multi-effect VST3 rack / chains | 🚧 Roadmap |
| Sidechain / advanced multi-bus routing | 🚧 Roadmap |
| Arbitrary multichannel / Float64 fallback | 🚧 Roadmap |
| macOS / Linux packages | Not currently shipped |
Compatibility with a specific third-party effect can still depend on its VST3 implementation and version. Reproducible compatibility reports are welcome.
The long-term direction is bigger than a single effect slot.
Stable single-effect hosting, automatic discovery, native vendor editors, state recovery, crash-isolated runtime and scanner, and a simple OBS filter workflow.
Multiple VST3 effects in one rack with ordered chains, bypass/reorder, rack presets, aggregate latency handling and a workflow designed for live use.
Flexible audio routing, sidechain paths, multi-bus handling and richer signal-flow control for broadcast chains.
VST3 instrument hosting, MIDI input/event routing, transport/clock-aware processing and a path toward playing software instruments directly in an OBS live-performance setup.
A creator should be able to build a studio-quality live audio rig inside OBS: effects chains for mastering-style stream processing, rack routing and sidechains for broadcast control, and eventually MIDI instruments for live performance—all through a workflow designed around isolation, recovery and reliability.
See ROADMAP.md for the engineering roadmap and scope boundaries.
The current Windows packages are not commercially Authenticode-signed, so Windows may show Unknown publisher or a SmartScreen reputation warning.
That warning is about publisher signing/reputation; it is not proof that the file is malicious. Keep Windows security enabled, download only from this repository's Releases page, and verify SHA256SUMS.txt when you want an additional integrity check.
Do not disable Defender or SmartScreen globally for this project.
This project is designed for crash containment, not malware containment. A VST3 is native software and still runs with your Windows user permissions inside the helper process. Only use plug-ins from vendors you trust.
Read Security and crash isolation for the exact boundary.
The public user experience is intentionally simple. Engineering details remain available for anyone who wants to audit the implementation:
- Product roadmap
- P1 architecture
- Original P0 isolation architecture
- Windows installation notes
- Security policy
- Third-party notices
Release CI builds against pinned OBS/libobs, runs protocol/lifecycle/scanner/recovery tests, validates the Windows package, smoke-tests the Smart Installer, and checks loading against the supported OBS compatibility floor.
Project code: GPL-3.0-or-later. See LICENSE.
The Steinberg VST3 SDK used by the build is MIT-licensed; see THIRD_PARTY_NOTICES.md.
VST is a trademark of Steinberg Media Technologies GmbH. OBS is a trademark of its respective owners. This independent open-source project is not endorsed by Steinberg or the OBS Project.