SkieIs incognito mode blocked on managed school devices?
Yes. Skie blocks incognito mode in Chrome as a device owner rule, so the option does not appear for students. Browsing stays under the same SafeSearch, safe-sites and DNS filtering as normal tabs. It is on by default and applies to Chrome stable, beta, dev and canary.
Incognito does not hide a user from the network, but it does skip some things admins rely on, such as extensions and in some cases history. Students also treat it as the first thing to try. Blocking it removes the temptation and a common question for staff.
Skie sets the Chrome incognito policy to disabled. The menu item is gone and links that try to open in a private tab open normally or not at all. Because it is enforced by the device owner, there is no setting for the student to change.
It is one of a set of Chrome rules that work as a package. Search engine locked to Google, sign-in blocked, sync disabled, pop-ups blocked and internal pages such as chrome://flags blocked all close off nearby routes. Blocking only one of them would leave an easy alternative.
What happens on the network side is unchanged. The filtering DNS applies to incognito and normal tabs, so even a browser that allowed private tabs would still be filtered. The incognito block is about visibility and consistency, not the only line of defence.
Practical tip: if a teacher reports a student 'browsing privately', check the device's effective policy. A missing block means the group is on a policy without the Chrome rules, or the device is not on the latest policy, both of which the dashboard shows.