Preparing VRChat for the future with Unity 6
VRChat is one of the largest social VR platforms. Players meet, play, and create in millions of worlds and avatars built by the community. Unity Studio Productions has worked with VRChat for several years on porting to new VR headsets, performance work, and backporting custom engine fixes. VRChat asked us for two things: The first was to move the platform from a custom build of Unity 2022.3 onto Unity 6. The second was to help bring the community's existing content to more devices, without breaking anything players and creators have spent years building.
+12% to +23%
Frame rate gain after the Unity 6 upgrade
1000 with 95.5% success rate
Android worlds rebuilt for iOS by the Shader Transpiler
The challenge
VRChat ran on a heavily customized fork of Unity 2022.3. Every Engine fix had to be carried forward by hand, and each upgrade cost more than the one before it. Moving to Unity 6 meant reintegrating that custom work and fixing the regressions that showed up across a huge range of hardware, including text rendering, input polling, and particle issues. Content was a separate problem. VRChat's user-generated worlds ship as pre-built asset bundles, with shaders compiled for a specific platform. Worlds built for Android couldn't run on iOS, and creators can't be asked to rebuild them, since many never will. Any solution had to convert that content automatically, with no source assets available. VRChat also wanted a regular release cadence throughout, with limited internal bandwidth to investigate bugs.
What we used
The core of the content work was a standalone Shader Transpiler tool that USP built and maintains, which runs on Windows and Linux. We ran regular syncs and shared Slack channels with VRChat's engineers. VRChat triaged incoming issues and USP owned the investigation and fixes.
What we did
Moving to Unity 6
First, we moved VRChat to Unity 6. The team reapplied or retired VRChat's custom Engine changes on top of Unity 6 and delivered builds to players on a roughly two-week cadence. USP owned investigation and fixes for Unity 6 bugs as they came in so VRChat's team could stay focused on their own roadmap and let the upgrade roll out to all players.
Converting compiled worlds for iOS
Second, we built the Shader Transpiler. Rather than ask creators to reupload content, the team built a standalone tool that takes existing asset bundles and converts their compiled shaders automatically. The tool converts Android worlds so they run on iOS. The first release was handed to VRChat in mid-2025, with documentation and sample bundles so their team could run it themselves.
Keeping converted content in step with the engine
Third, we brought the transpiler up to Unity 6. Once the Engine upgrade was live, the team moved the transpiler onto Unity 6 so converted content matches the Engine players are running. They also made it multithreaded by default, which cut batch conversion times, and confirmed builds on both Windows and Linux.
“Asset bundles have been both a curse and a blessing for VRChat. Working with Unity’s Professional Services team, we migrated pre-built content across platforms, something we once believed was impossible. Be careful how high you raise the bar: we’re going to expect a lot from you! ”
Jesse Joudrey - VRChat Inc.
CTO/Co-founder
The outcome
Unity 6 is now live for every VRChat player. VRChat announced the upgrade on its public YouTube channel in October 2026. Being on Unity 6 also makes future rendering improvements far easier to adopt. Players ran their own benchmarks across popular worlds after the switch and reported frame-rate gains. The Shader Transpiler lets VRChat bring existing Android worlds to iOS without creators rebuilding anything, and it has already converted 1000 worlds with 95.5% success rate. VRChat now holds the tool and its documentation, so its own team can rerun conversions whenever the Engine changes.
