Essentials

Horizon OS

Updated: Apr 6, 2026

Horizon OS is the operating system that powers Meta Quest headsets. Understanding its core features and capabilities helps you build apps that take full advantage of the platform, regardless of which engine or SDK you use.

Core features

Input — Controllers, hand tracking, gaze input, and microgestures

Audio — Spatial audio, voice input, and audio capture

Passthrough — Camera-based mixed reality with environment depth

Sharing — Screen sharing, casting, and social presence

Authentication — Meta account integration and user identity

Selfie camera — Front-facing camera for mixed reality and social features

Battery saver mode — Power management for extended sessions

Panel sizing — Window management for 2D panel apps

Ad attestation and ad ID — Advertising identity and attribution

Graphics and rendering

Quest uses a compositor to combine your app’s rendered frames with system UI and apply lens distortion for the display. A few key concepts:

Compositor layers — Render text and UI on separate layers for sharper quality. See Compositor layers

Fixed foveated rendering (FFR) — Reduce GPU workload by rendering the edges of the frame at lower resolution. Up to 25% performance improvement in pixel-intensive apps

Application SpaceWarp (AppSW) — Render at half frame rate while the system synthesizes intermediate frames, freeing up to 70% additional compute

Render scale — Dynamically adjust eye buffer resolution based on available GPU headroom

For engine-specific implementation, see the rendering guides for Unity, Unreal, or Native.

Performance and hardware

Quest dynamically manages CPU, GPU, memory, and thermals to balance performance and battery life. Key things to know:

CPU and GPU levels — Quest assigns discrete performance levels to processors. Higher levels mean more power but more heat. Your app can request specific levels. See CPU and GPU levels

Memory limits — PSS kill limits are 4.4 GiB (Quest 2, Quest Pro) and 5.75 GiB (Quest 3, Quest 3S). Exceeding these under memory pressure causes crashes. See Memory / RAM

Battery saver mode — A user setting that reduces brightness, caps refresh rate at 72 Hz, and disables GPU boosts. Your app should detect and adapt. See Battery saver mode

Boosting — Apps can request short CPU/GPU boosts for loading screens and transitions. See Boosting CPU and GPU levels