Essentials

Horizon OS

Updated: Aug 12, 2026
Horizon OS is the operating system that powers Meta’s family of immersive devices. 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.
Feature support and performance budgets vary by device. See Compare devices for per-model specs. See Compatibility mode to declare the devices your app supports.

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

Horizon OS 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
  • Foveated rendering (FFR) — Reduce GPU workload by rendering the edges of the frame at lower resolution. See Foveated rendering
  • Application SpaceWarp (AppSW) — Render at half frame rate while the system synthesizes intermediate frames. See App Spacewarp
  • Render scale — Dynamically adjust eye buffer resolution based on available GPU headroom. See Render scale
For engine-specific implementation, see the rendering guides for Unity, Unreal, or Native.

Performance and hardware

Horizon OS dynamically manages CPU, GPU, memory, and thermals to balance performance and battery life. Key things to know:
  • CPU and GPU levels — Horizon OS 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 — Horizon OS enforces a per-app memory (PSS) limit that varies by device. Exceeding it under memory pressure causes crashes. See Memory / RAM
  • Battery saver mode — A user setting that reduces power draw. It lowers the performance your app can rely on, so detect it 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

Immersive features

  • Scene understanding — Detecting walls, floors, furniture, and room layout
  • Spatial anchors — Placing persistent virtual content in physical spaces
  • Passthrough — Blending virtual content with the real world using the device’s cameras
  • Body tracking — Full-body pose estimation for avatars and gameplay
  • Eye tracking — Gaze direction for interaction, foveated rendering, and analytics
Availability varies by device. See Compare devices for per-model support. See Input and Immersive features for detail.

Design guidelines

For best practices on designing immersive experiences for Horizon OS:

Intro to immersive design

Learn more

For engine-specific implementation guides, visit the documentation for your build path:
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