AI Overlay for Canvas Quizzes with Respondus on Mac

· 3 min read
Canvas + Respondus · LMS exams

Canvas is the LMS used by most US universities; many courses run quizzes through Canvas with Respondus LockDown Browser as the secure delivery layer. The combination is so common that Mac students often ask whether the overlay works specifically for Canvas + Respondus.

When your professor enables "Require Respondus LockDown Browser" on a Canvas quiz, students must launch Respondus instead of Safari/Chrome to take it. Respondus loads the Canvas quiz inside its own Chromium-based wrapper and applies system-level lockdown (no Cmd-Tab, no screenshots, kiosk-style window). The lockdown does not change the capture pipeline; macOS still mediates all screen access and still honors window privacy. The LDBypass overlay sits in its own window with the privacy flag set, so any recording or live monitoring through Respondus + Monitor receives frames without the overlay.

Key points

How it works

┌── macOS host ─────────────────────────────────┐
│  ┌── proctor desktop app ───────┐             │
│  │  Calls ScreenCaptureKit /    │  ← misses   │
│  │  CGWindowListCreateImage     │    flagged  │
│  └──────────────────────────────┘    windows  │
│                                               │
│  ┌── LDBypass overlay window ───┐             │
│  │  sharingType = .none         │ ← invisible │
│  └──────────────────────────────┘   to capture│
└───────────────────────────────────────────────┘

Compatibility on Mac

macOS 14 Sonoma+Yes (required for window-privacy API)
Apple Silicon (M1/M2/M3/M4)Native arm64 build
Intel Macs (2019+)Universal binary supported
Canvas LMS (Instructure)Quiz host, no proctor surface of its own
Respondus LDB on top of CanvasStandard capture stack, window privacy honored

Common questions

Does the overlay work the same for Blackboard or Moodle quizzes with Respondus?

Yes. The LMS only hosts the quiz; the proctor surface is Respondus, and Respondus uses the same capture path on every LMS.

My professor uses Canvas without Respondus. Do I even need an overlay?

If there is no proctor and no recording, you can use any normal browser plus AI. The overlay matters when something is actively monitoring your screen.

Will Canvas show that I switched apps if I toggle the overlay?

Canvas itself does not monitor app switching. Respondus does, but the overlay does not steal focus from Respondus when you toggle it - the keyboard tap routes to whichever app you click into.