# Lockdown Browsers: What They Can See and What They Cannot

Source: https://examfence.com/blog/2026-11-15-lockdown-browsers-what-they-detect.html

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**Short answer:** A lockdown browser like Respondus LockDown Browser controls the exam machine: it blocks new tabs, copy and paste, screenshots, screen recording, and virtual machines, and it forces the exam to run in a single window. It cannot see anything off the machine. A phone on the desk, a note taped to the wall, or a second person in the room is outside its reach, which is why institutions pair it with webcam monitoring or a live proctor for high-stakes exams.

## What the browser actually locks

Respondus LockDown Browser, the most widely used tool in this category, turns the exam machine into a single-purpose device for the duration of the test. It blocks new tabs and windows, disables copy and paste, prevents screenshots and screen recording, blocks virtual machines, and prevents the student from opening other applications. The exam runs in a locked window, and the student cannot leave it without submitting or being flagged.

The tool is effective at what it is designed to do, which is to stop the student from looking up answers on the same machine. It is not designed to stop anything else. A student who opens the exam on a laptop and searches on a phone is using a device the browser never sees. A student who tapes notes to the wall behind the camera is using a surface the browser cannot inspect. A student who has a second person in the room is using a resource the browser cannot detect.

## What the camera adds, and what it does not

Adding webcam monitoring, Respondus Monitor or Honorlock's equivalent, closes some of those gaps and opens others. The camera records the student and the screen, and AI flags moments for human review: the student looking away, a face leaving the frame, a second face entering, or the screen going dark. The flags are bookmarks for a human reviewer, not verdicts. Honorlock's own documentation describes its AI as calling a live proctor only when something is flagged, and the proctor decides whether to intervene.

The limits are well documented. Face-detection systems fail more often on darker skin tones, on students wearing glasses, and on students in low light, which means the same exam produces more flags for some students than for others. A dropped video feed, a frozen frame, or a camera that disconnects mid-exam is a technical failure that looks identical to a cheating attempt in the log. And a student who knows where the camera points can keep the phone below the frame, which is why the camera is a deterrent and a record, not a guarantee.

## How institutions actually use it

About two-thirds of North American higher-education institutions use some form of online or automated proctoring, according to Educause's 2023 survey. The institutions that use it well match the tool to the stakes: a lockdown browser alone for a low-stakes quiz, a browser plus webcam recording for a midterm, and a live proctor for a final that decides a grade. The institutions that use it badly apply the highest level of surveillance to every assessment, which produces the most flags, the most appeals, and the most student complaints, and it teaches students to game the camera rather than to study.

The practical rule is to design the exam for the tool you have. If the browser cannot stop a phone, write questions that a phone cannot answer: questions that require applying a concept to a new scenario, not recalling a fact. A lockdown browser is a control on the machine. The exam design is the control on everything else. For the detection side, [how online exams detect tab switching](https://examfence.com/blog/2026-11-14-online-exams-detect-tab-switching.md) covers the signals the browser actually sees, and [face-detection failures in proctoring](https://examfence.com/blog/2026-11-14-proctoring-face-detection-failures.md) explains why the camera flags some students more than others.

## Frequently asked questions

### What does a lockdown browser block?

It blocks new tabs and windows, copy and paste, screenshots, screen recording, virtual machines, and other applications on the exam machine. The exam runs in a single locked window that the student cannot leave without submitting.

### Can a lockdown browser see my phone?

No. A lockdown browser controls only the machine it runs on. A second device, notes on the wall, or another person in the room is outside its reach, which is why institutions pair it with webcam monitoring for high-stakes exams.

### Does webcam proctoring decide if I cheated?

No. The AI flags moments for human review: looking away, a face leaving the frame, a second face entering. The flags are bookmarks, not verdicts, and a human reviewer or live proctor decides whether to act.

### Why do proctoring systems flag some students more than others?

Face-detection systems fail more often on darker skin tones, on students wearing glasses, and in low light. A dropped video feed or a frozen frame also looks identical to a cheating attempt in the log, which is why flagged exams need human review.