VRChat is an online virtual world platform created by Graham Gaylor and Jesse Joudrey and operated by VRChat, Inc. The platform allows users to interact with others with user-created 3D avatars and worlds. VRChat is designed primarily for use with virtual reality headsets, being available for Microsoft Windows PCs and as an app for Android-based headsets such as Meta Quest, Pico 4, and HTC Vive XR Elite. VRChat is also playable without a virtual reality device in a desktop mode designed for a mouse and keyboard, gamepad, or mobile app for touchscreen devices.

VRChat was first released as a Windows application for the Oculus Rift DK1 prototype on January 16, 2014. It was later released to the Steam early access program on February 1, 2017. VRChat later became available on the Meta Quest store on December 11, 2018, and in early access on Google Play on August 22, 2023, then was fully released on the App Store and Google Play store on October 24, 2025.

VRChat's functionality is similar to that of games such as Second Life and Habbo Hotel, allowing users to access user-developed "worlds" where they can interact with each other using virtual avatars. Worlds can vary, with some taking the form of social spaces, performance venues, and games.

VRChat is also capable of running in "desktop mode" without a VR headset, which is controlled using either a mouse and keyboard, gamepad, or touchscreen device. Some limitations exist in desktop mode, such as the inability to freely move an avatar's limbs, or perform interactions that require more than one hand.

The paid VRChat Plus (VRC+) subscription provides extra features such as more slots for "favorite" avatars, profile pictures, and the ability to attach an in-game photo to an invite request. Other exclusive features for subscribers have been added since launch, including additional theming options for the user interface, and custom emojis and stickers. In March 2025, several new Plus-exclusive features were launched in beta, including a virtual dolly for the in-game camera, a flyable camera drone, and "Selfie Expression"—a feature that allows users in desktop mode to use a webcam to give their avatar facial motion tracking without needing to use a VR headset.

Creating avatars and worlds is an involved process using external tools; they are uploaded by users of a Unity software development kit released alongside VRChat. Only a small subset of skilled users create avatars and worlds, which are then made available to the rest of the userbase. Avatars are capable of mimicking head and hand motion along with supporting lip syncing, eye tracking, blinking, and other features. Trends and variations of avatars can spread deeply through the community, and avatars themselves are often distributed for free, or sold through online marketplaces such as Gumroad or Booth.

In 2020, VRChat introduced Udon, a visual programming language which uses a node graph system. While still considered alpha software, it became usable on publicly-accessible worlds beginning in April 2020. A source-to-source compiler known as UdonSharp allows scripts to be written against the Udon APIs in C#.

In 2022, support for the Open Sound Control (OSC) protocol was added for more advanced interactions with external software and devices. Later in the year, VRChat began to implement a secondary application—"VRChat Creator Companion" (VCC)—for managing Unity IDE installations, projects, and packages using a Unity Package Manager (UPM)-compatible format. The previous VRChat SDK2 was deprecated in February 2023, with the Udon-based SDK 3.x becoming mandatory for all new content going forward.