Every trainer who moves an exam online asks the same question, and it is the right one to ask: if nobody is in the room, how do I stop people cheating? The honest answer is that you cannot make cheating impossible. What you can do is make it pointless, difficult, and, if it is attempted, provable. That combination is what keeps an online exam trustworthy.

Here is how to prevent cheating in online exams, layer by layer, without turning the sitting into an ordeal for the honest majority.

Make cheating pointless before you make it hard

The most powerful anti-cheating measure has nothing to do with cameras. It is the exam design itself. If every candidate sits the same fixed paper, the answers are worth stealing, and one leak spreads to everyone. If each candidate draws a different paper from a larger pool, a shared answer key is close to worthless.

So the first move is structural. Build a question bank large enough to randomise from, and shuffle both the questions and the answer order per candidate. You have now removed the single biggest incentive to cheat, which is that cheating scales. It no longer does.

Verify who is actually sitting the exam

The oldest form of cheating is the simplest: someone else takes the exam for you. No amount of screen monitoring catches an impersonator, because the impersonator behaves perfectly. You stop this at the door, with identity verification.

Before the first question loads, capture a photo of the candidate and a government ID, and match the two faces. On a high-stakes sitting, a proctor confirms the check. It is a small step that closes an entire category of cheating, and it is why identity verification belongs on any exam whose result actually counts.

Lock down the exam environment

Once the right person is in the seat, the goal is to make their screen behave like a supervised room. A browser-based exam lockdown keeps the candidate inside the exam: no wandering off to other applications, no opening the open web in the next tab, no pasting an answer in from somewhere else.

In practice that means a few controls working together:

  • Screen lock, so the exam holds focus for the whole sitting.
  • Tab-switch detection, which notices when the candidate leaves the exam window.
  • Copy-paste detection, which flags attempts to lift the question text out or drop an answer in.
  • Second-screen detection, which looks for signals that a second monitor is in play.

None of this needs a clunky desktop client. A good platform runs the whole locked-down sitting in a standard web browser, which removes the install step that usually generates the most support tickets on exam day.

Detect the behaviour, not just the person

Identity and lockdown handle the obvious routes. The subtler ones, a phone under the desk, a second person in the room, a candidate reading from another device, are caught by monitoring the sitting and flagging anything unusual.

This is where AI-powered cheating detection earns its place. Computer vision watches for phones, extra faces, and absent candidates, and marks the moment for review. On CandidatesPrep the vision runs in the candidate's own browser, so the platform gets the integrity signal without shipping a live video feed off to be analysed.

Live or AI: match the effort to the stakes

You do not need the same intensity on every exam. Live proctoring puts a human invigilator on the sitting in real time, which suits a high-value licence. AI proctoring, with a person reviewing the flags afterwards, scales to a large knowledge check. The point is to match the level of supervision to what is genuinely at stake, rather than over-policing a low-stakes quiz.

Keep a record you can defend

Here is the part that most anti-cheating advice skips, and it is the most important. Preventing cheating is not only about the moment of the exam. It is about what you can prove afterwards.

Record every proctored session, and treat each flag as evidence attached to a timestamp rather than an automatic verdict. When a result is challenged, and on a high-stakes exam one eventually will be, the recording and the flag log are already on file. The dispute becomes a review of the record instead of one person's word against another's. That is what makes a remote result defensible, which is the real goal. Catching cheating is a means to it.

What prevention is not

Be honest with yourself and with candidates about the limits. No system reads minds, and none catches everything. Overselling proctoring erodes the trust it is meant to protect. The realistic aim is to raise the cost of cheating and lower its ease until the result is trustworthy and, if questioned, provable. It is a deterrent plus an evidence trail, not a lie detector, and it should collect what it needs for integrity and no more.

The bottom line

Prevent cheating in online exams by stacking the layers: randomise the paper so cheating does not scale, verify identity so the right person sits it, lock down the browser, detect the behaviour with AI, and record everything so the result holds up. Do that, and a remote exam becomes as defensible as one run in a hall.

You can see the supervised side in the CandidatesPrep trainer console, read exactly how online proctoring works, or walk through the difference between a proctored and an unproctored sitting. To see it on your own exams, request a demo.