What coding interview platforms actually log, compared signal by signal

The five platforms side by side

HackerRank: the most specific list

HackerRank's Interview Integrity Signals article names four signals, and an admin has to enable the feature:

• Out of Interview: switching to another browser tab. Opening the browser console or interacting with a permission pop-up can trigger it too.
• Copy Paste: pasting from an external source. The article says this “does not always indicate misconduct”.
• Window Resize: resizing the browser window, which it says “may suggest attempts to access or conceal other applications or content”.
• Multi-Monitor Setup: with display access granted, it logs extra displays being connected or disconnected. It is “supported only on the Chrome browser”. If you do not grant access, the interviewer is told.

The interviewer does not get pinged for every event. A cluster becomes one “Multiple Suspicious Activities” alert, and a Suspicious Signals panel can stay open in real time, with each absence on the timeline. Tests have a separate, heavier stack, covered in can HackerRank detect AI.

CoderPad: focus and keystrokes, kept for later

CoderPad's cheating prevention guide says the interviewer is alerted when a candidate leaves the IDE or pastes from an external source. The playback documentation says the platform tracks “every keystroke of every participant”. Pastes appear as yellow dots, absences as orange dots with a tooltip such as “Clicked away for 19 seconds”, and copying a whole file raises its own alert.

Two details catch people out. Opening the browser console counts as leaving, and copying from the built-in AI Assist tab can still show as a paste. CoderPad's own warning is that “pasted code and leaving the IDE does not always equal cheating”. More in can CoderPad detect AI.

CodeSignal: a red light, and a score on tests

In a live CodeSignal interview, its activity indicator article describes a light near the top of the IDE: green while the candidate works there, red when they click away. It “cannot indicate where the candidate is navigating”, and it shows both live and in the replay.

Assessments work differently. The Suspicion Score combines similarity, paste events, description copying and typing telemetry per question. Proctored assessments record the camera, microphone and entire screen, so a focus signal matters less there. The full picture is in can CodeSignal detect AI.

Codility: fixed rules and a desktop app

Codility's Assessment Integrity Features article describes copy-paste and tab-switch tracking, shown in the candidate report and live to the interviewer in its Interview product. Similarity checks are not available in Interview. Signals roll up into a risk level of None, Low, Moderate or High using fixed rules, and Codility says it does not fail anyone automatically on an integrity signal.

The notable part is Device Integrity for Interviews, in preview: a desktop app for macOS and Windows that checks for known cheating tools. That is a different kind of check from anything a browser tab can do. See also can Codility detect AI and what to expect from a Codility test.

Karat: the interviewer is the detector

Karat publishes rules more than signals. Its customer FAQ says “all Karat interviews (including the interview audio and code playback) are recorded”, that interviewers “are taught to flag suspected use of any AI tools” in modules that bar them, and that the video and playback stay inside the Karat platform for the customer to review.

What you may use depends on the module. Karat's candidate FAQ allows looking up documentation during coding if you tell your Interview Engineer, and treats ChatGPT like a search engine for that purpose, but not for generating an approach or a solution. In its NextGen format, the built-in assistant is encouraged and “the use of external AI tools is prohibited”. See also what to expect from a Karat interview.

What these signals can and cannot know

The next point is our reading of the documentation, not a vendor statement. A web page learns about its own tab: whether it has focus, how big the window is, and, with permission, which displays exist. That is why “left for 19 seconds” is the typical record, and why none of these pages claims to log the site or app you moved to.

That limit does not make a session unobserved:

• The interviewer is still there. They hear pauses, watch your eyes on video, and can ask you to explain any line. HackerRank notes they can ask you to share your screen.
• Screen recording changes the picture. In proctored tests, other windows can simply appear in the recording.
• Desktop apps can see more. HackerRank's Desktop App Mode and Codility's app work outside the browser, and they are built for this.
• Replay shows how code arrived. A finished solution with no typing history reads badly whatever the source.

Innocent things that raise the same flags

Every vendor above says a signal is a reason to look, not a verdict. These normal actions produce the same events, so it helps to avoid them or say them out loud:

• Opening the browser console to debug counts as leaving on HackerRank and CoderPad.
• Answering a browser permission pop-up can count as leaving on HackerRank.
• Pasting from your own editor still looks like an external paste. Say what you are pasting.
• Resizing the window to fit a call next to the editor is a logged event on HackerRank. Arrange your windows before you start.
• Plugging in or unplugging a monitor mid-call is logged on HackerRank when display access is on. Connect it first.
• Looking something up where it is allowed. On Karat, the rule is to tell the interviewer first.

Where a desktop overlay fits in this

We make Interview Copilot, so read this with that in mind. It is a native desktop window that asks the operating system to leave it out of screen capture on macOS and Windows (Microsoft's documentation says plainly this is not a security guarantee). On Linux it is not hidden at all. Answers start on their own when the interviewer finishes, and it does not need a second monitor.

That changes only what appears in a screen share. It changes nothing in the table above: clicking into another window is still a focus change, typing and pasting still land in the replay, a desktop-app check may still look for tools like ours, and a person can still ask you to explain your code. We have not tested it against each platform's signals, so we make no claim about what they would record.

Most important, none of this decides what you are allowed to do. Many employers ban live AI help in writing, as our list of company AI interview policies shows. Check the rule for your round first.

Sources

Checked on 3 November 2026. Codility, CodeSignal and Karat's help pages refused our automated check, so for those we relied on their text as shown in search results and on the review in our earlier CodeSignal article. Features change and vary by plan, so check again before relying on a detail.

• HackerRank: Interview Integrity Signals
• HackerRank: Desktop App Mode
• CoderPad: Cheating prevention in Interview
• CoderPad: Playback mode
• CodeSignal: Can I see if a candidate clicks away from the IDE?
• CodeSignal: Using Suspicion Score
• CodeSignal: What is proctoring?
• Codility: Assessment Integrity Features
• Codility: Device Integrity for Interviews
• Karat: Customer FAQ
• Karat: Candidate Resource FAQ
• Karat: NextGen

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