Lockdown browser: Features, benefits & limitations

54.7% of respondents were found to have engaged in online exam cheating, according to an analysis of 19 surveys with more than 4,600 participants. 

With online assessment becoming the norm for education and recruitment, the question now is: how do we prevent cheating? 

Lockdown browsers attempt to answer this question. These secure environments will restrict screen activity, block unwanted apps, and create a distraction-free environment for candidates. 

So, to what extent could a lockdown browser work alone? What are its limitations? 

In this blog, we break down the features, benefits, and limitations of lockdown browsers, giving you the complete picture of when, why, and how to use them. 

Summarise this post with:

What is a lockdown browser?

A lockdown browser is a secure, purpose-built web browser designed to control the testing environment during an online exam. It locks everything outside the test window, so candidates cannot cheat, copy, or access any other materials.

Once launched, the lockdown browser takes over the entire system. Candidates can’t access other applications, switch tabs, use keyboard shortcuts like copy/paste, or even minimize the screen.

However, one thing people often overlook is that “Lockdown browser” isn’t just the name of a separate app. It also refers to a set of security features built into modern online assessment platforms.

For example, platforms (like Testlify) offer built-in lockdown functions such as:

• Full screen mode (can’t exit without auto flag)

• Tab proctoring (flags or blocks tab switching)

• Copy/paste restrictions.

• Mouse-out tracking

• Multiple monitor blocking

These features work directly inside the browser; no extra installation is needed. They’re common in remote hiring tests or professional certification exams.

Even in physical test centers or hallroom setups, many exams are conducted digitally. In those cases, the computers used by candidates often have a pre-installed lockdown browser.

This setup is typical for:

• Government exams
  
• Campus-based recruitment tests
  
• Board exams are conducted on computers.
  
• Entrance tests hosted in physical centers

For these offline-on-online tests, the lockdown browser creates a controlled digital shell, similar to how invigilators ensure discipline in the room.

Core features that secure the testing environment

The purpose of a lockdown browser is to have some degree of control over what the candidate is allowed to do during their exam. Its main objective is to create a cheat-proof testing environment from start to finish.

Below are the core features that make Lockdown Browser effective:

1. Blocks access to other applications

Once the lockdown browser is launched, candidates can’t open any other software. Messaging tools, browsers, file explorers, and even instant messaging apps are fully disabled.

2. Full-screen mode with no exit

The exam opens in full screen, and you can’t minimize, resize, or close it until the test is submitted. Any attempt to exit is either blocked or flagged for review.

3. Tab and navigation control

It blocks new tabs and turns off all browser functions, such as “Back,” “Forward,” and “Refresh.” You can only navigate to the exam, nothing else.

Advanced platforms like Testlify also track tab switching (also known as tab proctoring) and instantly alert administrators if a candidate attempts to switch screens.

4. Keyboard and shortcut restrictions

The browser turns off all major shortcuts like:

• Copy/paste (CTRL+C / CTRL+V)
• ALT+TAB (switch windows)
• Right-click functions
• Print screen or screenshot keys

This feature ensures test content stays secure and can’t be shared. Administrators can set limitations on the tolerance for violations. 

5. Detects multiple monitors

If a second screen is connected, the test won’t start. This helps ensure candidates can’t use another display to look up answers.

6. Dual camera proctoring

Testlify’s dual camera proctoring. This adds a second camera, typically from a phone or tablet, to monitor the candidate’s environment from a different angle. It helps detect side notes, other devices, or if someone else is present.

7. AI-generated answer detection

Modern lockdown setups include AI-powered detection for copied or AI-written responses. The system can flag unusual phrasing, GPT-like text patterns, or the use of unauthorized AI tools, especially during coding tests or when evaluating subjective answers.

Some tools (like Respondus) are standalone applications. Platforms like Testlify offer lockdown controls directly into the test flow with no extra installation required.

Together, these features build a strong wall around the test. They help prevent cheating, detect AI-generated answers, and ensure every online exam remains fair.

Benefits of using a lockdown browser

In every online exam, an element of trust is involved. However, this trust will be broken quickly if the examiners have no control over what candidates can access on their screens. 

That explains why many organizations opt for a lockdown browser configuration. Here is what makes it beyond just restriction:

1. Protects exam integrity
2. Easy to launch and use
3. Reduces the need for human invigilators
4. Useful in both remote and in-center tests
5. Supports cross-platform compatibility
6. Keeps things fair for everyone

A lockdown browser does more than just block shortcuts: it ensures that the test is being taken seriously. It’s not a perfect solution, but it sets a clear boundary. And sometimes, that’s all you need to keep things honest.  

“If you think technology can solve your security problems, then you don’t understand the problems and you don’t understand the technology” – Bruce Schneier, Cryptographer and Security Technologist

Limitations you must be aware of

A lockdown browser adds strong control to the testing environment, but it has limits, and knowing them helps you plan better. Below are the key challenges:

1. Cannot detect phones or other devices: A lockdown browser controls what’s on the candidate’s screen. But it can’t see what’s happening around it. A person can still use a phone, smartwatch, or another device nearby.

2. Doesn’t flag behavior: The browser restricts access, but it doesn’t “watch” the candidate. It won’t flag if someone is reading notes off-screen or talking to someone else unless paired with AI proctoring.

3. No room or eye movement tracking: Some test-takers use second screens, mirror displays, or external tools to aid in their test-taking. If not paired with multiple checks, even a locked browser can be worked around.

4. Setup can be a barrier: To start the test, users must install the lockdown browser from their applications folder. For Mac users, this often requires giving extra permissions. Some system requirements can cause launch issues or block access.

5. Tech conflicts happen:  Antivirus software, an outdated Operating System (OS), or weak internet can cause the browser to crash or freeze. In high-pressure exams, that adds stress for the candidate and the exam team.

Final thoughts: Is a lockdown browser enough?

A lockdown browser does a lot; it locks the screen, blocks shortcuts, and secures the testing environment. But it’s not the full picture.

For high-stakes online exams, the loopholes really matter. Especially when it is a remote test, where no physical invigilator is present, that’s why many organizations go beyond the lockdown browser. The bottom line?

A lockdown browser is basically a great starting point. But when the stakes are high, it works best as part of a layered setup. 

Testlify offers built-in lockdown controls, AI-assisted monitoring, and customizable proctoring flows, all in one seamless platform. Pure, trustworthy test security that scales according to your needs.