You can discourage candidates from switching tabs during the quiz. You can either end a candidate's attempt after a set number of tab switches, or only record how many times they switch tabs.
Proctoring settings are available only when candidates have to sign in to take the quiz. If the Proctoring page says that proctoring is disabled, turn on Require candidate sign in under Settings > Security first.
Terminate an attempt after a certain number of tab switches
Go to the Settings tab.
Click Proctoring.
Turn on the Terminate quiz session after tab switches toggle and enter a number. The candidate's attempt ends after that many tab switches.
Click Save changes.
Turning this on also turns on Tab proctoring, so the tab switches are recorded too.
Record the number of tab switches
Go to the Settings tab.
Click Proctoring.
Turn on the Tab proctoring toggle.
Click Save changes.
When a candidate switches tabs, they see a warning that this may affect their result. You can see how many times each candidate changed tabs in the Submissions section under the Results tab.
Tab proctoring and Terminate quiz session after tab switches both turn on Force full screen mode, because they work best in full screen. If you turn off Force full screen mode later, both settings turn off too.
Candidates can't take the quiz on a phone while either of these settings is on. They see a message asking them to open the quiz from a computer.