Welcome to the Developer Update for December 4, 2025.
Today’s featured world is Crimas by WispyWoo.
Announcements
New Years 2026 is Coming! Submit Something!
New Year’s Eve is almost upon us, which means it’s time to start creating. POSTERS! MUSIC VENUE LOGOS! ENTERTAINMENT NETWORK VIDEOS! You name it! As usual, the booths will be invite-only this year. Everything else is accepting public submissions!
SUBMISSIONS CLOSE WEDNESDAY DECEMBER 10TH AT 12PM PACIFIC TIME. There are no extensions, no late submissions, no exceptions!
We hope you look forward to this year’s world, we started working on it right now!
Submit a poster: https://forms.gle/JQKpvbtFBBv1xxTH7
Submit a music venue logo: https://forms.gle/2dX8SLmWGnyPrkmbA
Submit an Entertainment Network video: https://forms.gle/D1JUigG7xwoW3SWW8
Vket Winter 2025 Starts Tomorrow!
Starting on December 5 at 5pm PST, Vket Winter 2025 will be available only in VRChat!
More than 700 creators will showcase avatars, 3D models, Groups, and communities! It’s a literal virtual market all in VRChat.
Discover new avatar creators, world assets, events, and Groups throughout the 19 exhibition worlds!
Learn more here: バーチャルマーケット2025 Winter
2025.4.2 is Out!
We released 2025.4.2 this week!
It brings Group and Event Sharing, Group Discovery, Mutuals, and of course… Steam Audio!
Watch the Patch Notes Video here:
Alternative, you can read the full change log here.
Speaking of Steam Audio…
New Content???
Soon. Maybe tonight? 
Steam Audio!
Need we say more? … Okay, maybe we do. It’s out!!! Starting with VRChat version 2025.4.2, Steam Audio is now the spatializer used on all platforms.
Join us in celebrating with the community on the infamous https://issteamaudiooutyet.com/ website!
FAQ - Biggest Questions Up Front
Does Steam Audio require Steam?
No. It runs on all platforms and devices. It is only called Steam Audio because Valve is building it.
When can we use all the cool features Steam Audio adds?
Certain aspects of Steam Audio will require an update to our world SDK. We don’t have a timeline for this, but we would like to do it.
Until then, features like occlusion, reflections, audio raytracing, etc. will not be available.
Do I need to update my content?
Maybe!
We have an extensive conversion layer (more on that below), but in some edge cases you may need to adjust audio sources in your worlds or on avatars.
Our experience over the past 2 months of open-beta has shown that almost all content will work without any adjustments however.
You broke audio, everything sounds bad, I will yell and nobody will hear because it’s so broken!!1!
First off: Give it some time!
We know this can be frustrating, but a lot of feedback we have received is that people initially dislike it, but after using it for a week never want to go back. Yes, really.
Brains are weird when it comes to hearing!
Certain aspects of Audio are different from our previous spatializer, ONSP, and will remain so. For example: The way sound sources encode their direction relative to you will be different. This is intentional, and while we will continue to tweak it as time goes on, the overall change is here to stay.
We are aware that for a small minority of people, some aspects of Steam Audio may actually end up sounding slightly worse.
This is an unfortunate reality of psychoacoustics, and building systems that need to work for a broad mass of people. You can’t make a “perfect” spatializer. The good news is that we believe it will overall cause issues for fewer people than ONSP did!
Finally: No, we will not revert Steam Audio. It is here to stay.
So, what is Steam Audio?
Up until now, VRChat has used ONSP as our audio spatializer. A spatializer is the part of the audio processing chain that makes directional hearing work.
That is, it allows you to hear sounds as if they are off to your side, above or below you, and to your front or back. It also handles some secondary processing, like distance falloffs, so-called “direct effects” like air absorption and source directionality, some extra gain handling, etc.
For a long time now, we’ve been testing Steam Audio in a series of betas, as we’ve wanted to move away from ONSP.
Why move away? Well, a lot of reasons – ONSP does not function on iOS for example. Steam Audio is open-source and allows us to fix issues ourselves, it is actively maintained by Valve, and it opens the door to some effects that were not possible before (Audio Raytracing! Reflections! Wall muffling!). We also (personally) think that Steam Audio simply sounds better.
Additionally, it handles situations like crowded instances or conversation circles a lot better, and the EQ applied to world sources is flatter, leading to less distortion.
Notes on ONSP Conversion
Steam Audio uses a completely different paradigm for how Audio Sources are configured in Unity. To ensure existing content doesn’t break, we have built an extensive ONSP->Steam Audio conversion layer.
You can continue to create worlds and avatars with the VRCSpatialAudioSource component just like before, and we will convert it under the hood once you load it in VRChat.
We have spent many years (literally!) tweaking this to preserve content as best as possible, going as far as modifying the native processing code itself.
Most worlds and avatars should continue to work exactly like they did before. However, this does not mean there won’t be edge cases!
You can report any actual issues https://feedback.vrchat.com, though note that we will be looking out specifically for functional bugs.
This includes audio levels changing drastically, falloff curves not being respected, or ranges not applying the same. Things will sound different in some scenarios however, for example direction and audible distance cues, or minor shifts in tonality, EQ or mixing.
We are aware that the ONSP conversion isn’t perfect. But we chose to mark this as our cutoff point where it is good enough for almost all content. The remaining edge cases can be addressed by further patches on our side, world and avatar creators updating their content with Steam Audio in mind, and in the future by switching to a Steam Audio enabled SDK (once one becomes available).
On a different note, Voice audio specifically has received a slight tune-up. While we tried to preserve compatibility with the VRCPlayerApi functions available, this was the one place where we intentionally did not aim for a 1:1 conversion from ONSP. Voice audio is the backbone of our platform (imagine “VRChat” without the “Chat”???), so we took some liberties towards compatibility and instead focused a bit more on actual improvements made possible by the switch.
This includes slightly different falloff curves, different EQ and compressor tuning, as well as adding source-directionality. The latter part meaning that someone speaking away from you will sound different than someone talking directly at you, which helps a ton when moving through large crowds.
On the Future of Steam Audio
Releasing Steam Audio to our live branch has been the biggest step in improving our audio pipeline – but it will not be the last!
We already mentioned that we plan on eventually shipping Steam Audio in the SDK with a lot of added functionality. This may also include some additional, highly requested Audio-related features.
In addition, we are looking at a refactor to our microphone pipeline. Steam Audio only affects the audio output path, but our audio input could also do with some modernization. We’ll have more details on that when the time is here, but suffice to say we are aware of our current shortcomings in that area.
And lastly, Steam Audio is open source. While some of our adjustments may remain private, we do plan on contributing some of the changes and adaptations we have made back to the community. We may also have a more technical, long-form writeup about Steam Audio in VRChat coming - stay tuned!
A big thank you to everyone who helped test Steam Audio over the years! This would not have been possible without all the input from the community <3
Dynamics on Items
Last week, we released a version of the SDK that includes the ability to add dynamics components (PhysBones, Contacts and VRChat Constraints) to world projects.
Internally, we’ve also added support for them on Items!
As a trial run, we’re planning to add Contacts to the Campfire and Marshmallow items that were available back in September and October.
This means you’ll be able to hold a marshmallow over the campfire and cook it that way. You should even be able to cook it over a fire on an avatar or in a world, provided they have a contact sender with the Fire tag applied!
(As a note, keen readers might have noticed this referenced in the 2025.4.2 patch notes!)
This system opens up a lot more possibilities for items in the future, and this is just the start of what we’re thinking of doing with them – stay tuned!
VRChat Success Stories: SpookyGhostBoo!
We’re publishing a short series of articles over the next few weeks about content creators that have had major success on VRChat.
You can read the first one here, detailing how SpookyGhostBoo, creator of the Black Cat, used the Creator Economy to increase her earnings by 4x!
Creators Fixes & Improvements
Here are some feedback items we’ve resolved since the past Dev Update!
₍₍⚞(˶˃ ᵕ ˂˶)⚟⁾⁾
World Dynamics Udon Feedback
As you may have already seen, we made these changes to how PhysBones and Contacts integrate with worlds in Udon:
- The Contact receiver involved in a Contact event is now included as part of the
OnContactEnterandOnContactExitcallbacks. This makes it possible to check if the receiver matches a particular one in your world. - Grabbing a PhysBone in ClientSim in an SDK project now gives you a reference to the simulated player.
SDK Build Target Fix
There was a bug in the SDK where if you applied platform specific overrides to any of your assets (textures, etc.), it would show you validation messages for that platform instead of the one you actually applied. That shouldn’t happen anymore in a future release.
Avatar Styles and Acknowledgements
A server-side issue meant the list of styles and acknowledgements used by avatars wouldn’t always be reliably passed to the client if the avatar you were looking at was private and worn by someone else in the instance with you.
This should now be fixed!
Conclusion
That’s it for this week! Next Dev Update will be on December 18… and that’s the last one of the year! See you then!
