Does Codility Detect Tab Switching and Copy-Paste?

Yes, and part of it is visible on every Codility Screen report, proctoring or not. As of September 9, 2026, Codility's report guide documents a task timeline that marks when the candidate was "Out of focus" and where "Text pasted into the editor." When the employer enables proctoring, those become tracked behavioral events: tab switches away from the Codility tab, paste attempts with the pasted code logged, attempts to copy the task description, and unusually fast completion. In Codility Interview, the interviewer sees the same events live. What Codility cannot see is the content of another tab.

What every report shows

Codility's guide to reading a candidate report describes the task timeline legend: "Dark blue line: Actively present in the IDE," "Light blue line: Out of focus," "Pink Arrow: Text pasted into the editor," "White Arrow: Verification attempt," and "Blue Arrow: Final code of your candidate."

That timeline is part of the standard report. A reviewer can see how long the test tab was out of focus and where pastes landed without any proctoring setting. The same page adds Codility's own caveat: "just because something was pasted into the editor, it doesn't mean that the candidate cheated. A lot of candidates like to use their own IDE for writing the bulk of the code, and then fine-tune it inside our editor as they run verifications."

What proctoring adds

When the employer enables behavioral proctoring, which Codility documents as "disabled by default," the Proctoring documentation lists four events on top of the timeline:

• Copy-Paste Tracking "monitors any attempts made by candidates to paste code into the solution area of the IDE. Events related to copy-pasting will also be listed in the Timeline tab of the candidate report, allowing recruiters to inspect the pasted code."
• Tab Switching "monitors whether candidates navigate away from the Codility browser tab to engage in other activities."
• Copying a Task Description catches "Candidates attempting to copy the task description, despite the inability to copy it within the IDE." Codility adds that this "could indicate a candidate's attempt to look up the task or employ AI platforms like ChatGPT."
• Time Spent on a Task flags "Abnormally short durations of time spent on a task, compared to the expected timeframe."

These feed the Assessment Integrity widget and an Integrity Risk level of None, Low, Moderate, or High. The intro page discloses which signals are on, "informing them of the specific behaviors that will be visible to recruiters."

The task description is the one thing you cannot copy at all. The IDE blocks it, and the attempt itself is the signal.

What a tab switch cannot reveal

A browser tab receives focus and visibility events about itself. It does not receive the URL, title, or content of any other tab. Codility's tab-switching signal therefore records that you left and for how long, not where you went. The browser-level mechanics are in how interview websites detect tab switching.

Two Codility features change that picture when enabled. Proctoring Snapshots are taken "periodically and when a suspicious behavior occurs," so a switch can trigger a screenshot of whatever surface you shared. And the Codility App, used for Device Integrity, "can detect cheating tools running on the device," though its documentation says it "does not record the candidate's screen, monitor keystrokes." Both are described in whether Codility records your screen.

Paste, your own IDE, and the rules

Codility's candidate FAQ permits external editors when the employer does. The own-IDE answer states: "You should follow the policy communicated by your test. If permitted, you can write your solution in an editor of your choice and paste the solution back into the Codility interface." A paste under that policy is expected, and the report shows it either way.

The line Codility draws is about people and policy, not the clipboard. Its FAQ on outside help says: "During the assessment, you must work on your own. You may not consult with or seek help from other people. Review the assessment policies included in your test link to determine if the use of other resources if permitted by the testing organization."

Paste also feeds a second system. Codility's Similarity Check compares submissions against 12 million prior assessments and against AI-generated solutions, and its Typing Pattern Detection looks at how code arrived in the editor. A paste avoids the typing signal and lands in the similarity signal instead; retyping does the reverse. Both are covered in whether Codility can detect ChatGPT. The generic browser side of paste events is in how interview websites detect copy and paste.

In Codility Interview

Codility Interview, formerly CodeLive, surfaces the same events to the interviewer while you work. The live proctoring signals page lists notifications for "switching browser tabs, losing browser focus, attempting to copy the task description, and copying external code (in basic IDE)." The Interview overview adds that for pastes "the system displays both the number of lines of code pasted and the code itself." Codility states these "signals are not visible to candidates."

What this means for candidates

Assume the timeline records every loss of focus and every paste, with the pasted text readable by the reviewer. Keep the test tab in front, silence notifications, and if the policy allows an external editor, expect the paste to appear and be ready to say what it was. Do not try to copy the task description; the block is the tell. When the policy is unclear, ask the test administrator before you press Start. The full list of what Codility records and flags is in what Codility detects.