PCVR setup guides throw around OpenXR, OpenVR, SteamVR, and runtime as though everyone already knows what they mean. They are related, but they are not interchangeable.
The short version:
- OpenXR is a modern cross-platform standard/API for XR applications.
- OpenVR is Valve's older VR API commonly associated with SteamVR.
- SteamVR is Valve's VR platform/runtime and software environment.
- An OpenXR runtime is the software implementation that connects an OpenXR app to your actual headset stack.
For VR mods, the correct choice is usually the one recommended by the mod or game-specific profile.
What is OpenXR?
OpenXR is an open standard from the Khronos Group designed to let XR applications target a common API instead of writing separate support for every headset ecosystem.
A game or mod can speak OpenXR while the active runtime handles communication with the headset.
That runtime might come from:
- A headset vendor.
- SteamVR.
- A PCVR streaming solution.
- Another compatible platform implementation.
This is why simply saying "I use OpenXR" does not fully describe a PCVR setup. The active OpenXR runtime also matters.
What is OpenVR?
OpenVR is Valve's older VR software development API. In normal PC gaming conversations, using OpenVR generally means the application is going through SteamVR.
Many older native VR games and mods were built around OpenVR, and it remains relevant because compatibility can be excellent.
UEVR currently supports both OpenVR and OpenXR.
What is SteamVR?
SteamVR is Valve's PC VR platform. It handles headset tracking, controllers, VR application launching, overlays, settings, and runtime functions for supported hardware.
SteamVR can be involved in multiple ways:
- An OpenVR app can run through SteamVR.
- SteamVR can act as an OpenXR runtime.
- Steam Link can stream SteamVR wirelessly to supported headsets.
So OpenXR vs SteamVR is not always a true either/or comparison. OpenXR applications can sometimes run through SteamVR as the active OpenXR runtime.
What is an OpenXR runtime?
Think of OpenXR as a common language and the runtime as the interpreter that connects that language to your headset system.
Only one runtime is normally active as the system's default OpenXR runtime at a time.
If the wrong runtime is active, an OpenXR game may:
- Launch in the wrong VR software.
- Fail to detect the headset.
- Open on the monitor only.
- Have performance or tracking issues.
OpenXR vs OpenVR in UEVR
UEVR's current documentation says:
- OpenVR generally has strong compatibility.
- OpenXR can offer higher performance when it works well with the headset's native OpenXR runtime.
- OpenVR requires SteamVR.
- OpenXR requires a valid OpenXR runtime and can also run through SteamVR if SteamVR is configured as that runtime.
This means the best UEVR choice is game- and headset-specific.
Use this priority:
- PCVR Central game/profile recommendation.
- UEVR profile author's instructions.
- Your headset/streaming application's supported runtime.
- Personal benchmark only if both paths are supported.
Quest: Meta runtime, SteamVR, Steam Link and Virtual Desktop
Quest PCVR can be connected in several ways, so two Quest owners can both say "I'm using OpenXR" while actually using different runtime paths.
That is why troubleshooting should record the entire chain, for example:
Quest 3 → Virtual Desktop → OpenXR → UEVR → Game
or
Quest 3 → Steam Link → SteamVR → OpenVR → UEVR → Game
A complete chain is much more useful than simply saying "UEVR crashes."
Does OpenXR automatically perform better?
No.
OpenXR can eliminate an unnecessary compatibility layer in some setups, but performance depends on the specific runtime, headset, game, mod, rendering method, and driver stack.
If a tested profile says OpenVR is required for correct rendering, a theoretical performance advantage means nothing if OpenXR breaks the game.
Does SteamVR always add huge overhead?
Not necessarily. Runtime overhead exists, but sweeping claims such as "SteamVR costs 20% FPS" are not reliable across every headset and game.
Measure your own CPU/GPU frame times under equivalent settings.
What happened to OpenXR Toolkit?
OpenXR Toolkit is separate from OpenXR itself.
The third-party OpenXR Toolkit project was discontinued in 2024. Its developer says there is no new development or tech support and recommends against installing/using it because it is known to cause issues with many newer games.
Do not confuse that with OpenXR being discontinued. OpenXR remains a current standard.
This distinction matters because old VR optimization guides sometimes recommend OpenXR Toolkit as though it were still a universal must-have.
How to choose a runtime for a VR mod
If the mod says OpenXR only
Use the correct OpenXR runtime for your headset/streaming setup.
If the mod says OpenVR only
Install and use SteamVR as required.
If the mod supports both
Use the profile's preferred option first. Benchmark the alternative only after you have a stable baseline.
If the mod says nothing
Check the game's PCVR Central listing and the original project documentation before guessing.
Troubleshooting runtime problems
Symptoms of a wrong or broken runtime can include:
- Headset not detected.
- Game launches only on desktop.
- Two VR platforms open unexpectedly.
- Controllers missing.
- Head rotation feels delayed or incorrect.
- Injection works but no VR image appears.
Write down your complete stack before changing anything.
Example troubleshooting note:
- Headset: Quest 3
- Connection: Virtual Desktop
- Runtime: OpenXR
- Tool: UEVR
- Game: Example Game
- Profile: v1.2
- Rendering API: DX12
That gives somebody enough information to help.
Frequently asked questions
Is OpenXR better than SteamVR?
They are not direct equivalents. SteamVR can itself provide an OpenXR runtime. The best path depends on the application and headset.
Is OpenVR the same as SteamVR?
No, but OpenVR applications are strongly associated with running through SteamVR.
Do I need SteamVR for UEVR?
You need SteamVR for UEVR's OpenVR path. OpenXR can use a different active OpenXR runtime when supported.
Is OpenXR Toolkit required for OpenXR?
No. OpenXR Toolkit was an optional third-party enhancement layer and is discontinued. OpenXR itself does not depend on it.
Can I have multiple OpenXR runtimes installed?
Yes, but one is generally selected as the active default runtime at a time. VR platform software often provides a way to set itself as the active runtime.
Related guides
Sources and further reading
- UEVR documentation: https://docs.uevr.io/
- Khronos OpenXR: https://www.khronos.org/openxr/
- SteamVR: https://store.steampowered.com/app/250820/SteamVR/
- OpenXR Toolkit releases/discontinuation notice: https://github.com/mbucchia/OpenXR-Toolkit/releases