Can HackerRank detect cheating? What HackerRank, CoderPad and Codility check

Coding platforms have added a lot of integrity tooling since AI helpers arrived. Much of it is opt-in, some of it comes with an add-on, and all of it is about the test window. Here is what HackerRank, CoderPad and Codility say they check, from their own documentation, and where the gaps sit.

What HackerRank checks by default

HackerRank says it "provides basic integrity features by default. These features require no additional setup." Two are on for every test:

• Copy and paste tracking.
• Tab proctoring, which tracks "how often and for how long a candidate leaves the test window".

That is useful context for a reviewer. It does not show what was on the rest of the screen.

Can HackerRank detect ChatGPT?

HackerRank's plagiarism model looks at the code itself. In 2023 HackerRank said it "repeatedly detects ChatGPT-generated solutions, even when those results are typed in manually", and claimed "93% accuracy". It did not define what that number measures, so treat it as a vendor claim.

Proctor Mode adds a second angle: it checks screenshots for "External AI coding assistants, such as third-party AI tools or copilots" and "Specialized browser extensions or invisible overlay applications".

Proctor Mode and Desktop App Mode

The stronger checks are part of HackerRank's AI Add-on, and a team has to switch them on.

Can HackerRank see your screen?

Only in Proctor Mode, or Desktop App Mode, which builds on it. In Proctor Mode the candidate is prompted to share the entire screen, and HackerRank takes periodic screenshots. By default, it tracks tab changes and pastes.

Whether a screenshot includes a window that has asked to be left out of capture depends on how the screenshot is taken. HackerRank's documentation says it looks for "invisible overlay applications"; it does not say how, and it does not say either way whether such windows show up. On Windows, such a window "is displayed only on a monitor. Everywhere else, the window does not appear at all."

What CoderPad checks

In live interviews, CoderPad alerts the interviewer when a candidate "Pastes code from an external source" or "Leaves the IDE (e.g., tab-switching)". "Every pad records a complete timeline of the session," so you can play back how the code was written. CoderPad says alerts "are most effective when paired with active interviewer response", and offers another route for AI: "Enable AI Assist for candidates so all AI usage is visible within the platform".

For screening tests, CoderPad Screen offers "Code similarity detection, playback to spot abnormal copy/paste, IP tracking, and IDE exit tracking", plus "Automated webcam screenshots analyzed by AI to flag suspicious behavior when required".

What Codility checks

Codility's desktop app offers cheating apps detection, "designed to surface apps that request exclusion from screen capture, the technique tools like InterviewCoder and similar overlay tools use to stay invisible to standard proctoring". It hands that evidence to a person: "Codility does not auto-fail a candidate on a detection." Visual and video proctoring is a Premium feature.

CodeSignal, another assessment platform, describes a "proprietary Suspicion Score, full-session proctoring", and reports its attempt rate on proctored assessments reached 35% in 2025.

Helpers that claim to beat these platforms

Helper tools name these platforms directly. Final Round AI says it is "100% invisible on ... HackerRank, CoderPad". Interview Coder lists HackerRank, CoderPad and Codility. Set those claims against what the platforms document: HackerRank's Desktop App Mode blocks other applications, Cluely by name, and Codility looks for the very screen-capture exclusion these tools rely on. More on the tools themselves is in Cluely vs Interview Coder.

The gap: the video call around the test

These platforms describe checks for their own test and pad. A live coding round also runs on a video call, and the call shows only what screen sharing carries. A second device or someone off camera sits outside both the coding window and the shared screen.

A helper window left out of screen capture is a separate case. For that hidden helper window, Verified Call looks for hidden AI tools: AI answer helpers like Cluely and Interview Coder that hide from screen sharing. It never joins the call. It plugs into the calls you already run. Google Meet today, actively expanding to Zoom and Teams. Our own testing: 4 free AI answer tools (Interview Coder, OpenCluely, Pluely and Cheating Daddy), each opened 30 times, plus 30 runs with no AI tool and 30 with everyday apps open. Each tool was found in 30 of 30 tries, with 0 of 30 false alarms with no AI tool open and 0 of 30 with everyday apps open (October 4, 2026). See the Research page.

A settings checklist for hiring teams

1. Keep the default tab and paste tracking, and read it in every report.
2. Turn on Proctor Mode where a test matters, and Desktop App Mode where other apps must be blocked.
3. Use custom or modified questions. Known questions are the easiest for AI; see cheating in coding interviews.
4. Watch the playback for pasted blocks and long silent gaps.
5. Follow every take-home test with a short live round on the same code.
6. Treat a flag as a reason to ask, not a verdict. See why false-alarm rates matter.