This post will quickly go over the launch options that you can apply from your Steam library to modify some parameters of the VRChat client. These can be useful if you want to make VRChat run borderless, in fullscreen mode, in a different monitor or if you want to modify the size of the window of the client when it launches.
|-screen-width 1920||Specifies window width|
|-screen-height 1080||Specifies window height|
|-adapter 1||Selects monitor that VRChat will launch in. Replace 1 with your monitor #.|
|-screen-fullscreen 1||Launches VRChat in Fullscreen mode if set to 1, otherwise launches it in windowed mode (if set to 0). You can also use ALT+ENTER to switch between these without having to add any launch options.|
Setting launch options for a Steam game or app is easy and the steps are the same for every game.
VRChat documentation lists the following launch options, which seem to be mostly aimed at developers. I will list them here, perhaps you will find them useful.
|–no-vr||Forces Desktop mode|
|–profile=X||Launches with a different user profile, where X is a number. 0 is the default profile|
|–enable-debug-gui||Enables debug menu shortcuts, see Keyboard and Mouse for shortcut keys|
|–enable-sdk-log-levels||Enables a large amount of SDK2 logging for Triggers/Actions Warning: Will cause your log to get quite large!|
|–enable-udon-debug-logging||Enable Udon heap and stack dumps in the client. Usually only enabled in editor Warning: May cause your log to get quite large in Udon worlds that are having issues!|
|–legacy-fbt-calibrate||Forces the legacy method of Full-Body Tracking calibration|
|–disable-friendsync||Forces the legacy method of updating your Social menu|
There are some additional launch options that games made in Unity have (VR Chat is one of them), but it is unclear whether these options have an effect on performance or anything at all. I will list them regardless, just in case.
|-force-d3d9||Forces the game to run in DirectX 9|
|-force-d3d11||Forces the game to run in DirectX 11|
|-force-d3d11-no-singlethreaded||Forces the game to run in DirectX 11 multi-threaded|
If you are using Oculus, you must create a shortcut to the VRChat executable. After launching Oculus Home, launch this shortcut by clicking its icon. The Oculus launcher does not support launch options natively.