A teacher walks through rows of desks halfway through a lesson and finds three students playing Minecraft. She redirects them and closes the tabs, and returns to the lesson, but ten minutes later the students are back to mining and crafting. The students opened the game from files saved on their Chromebooks, and the school’s web filter never saw it.
For students, the game has changed. Browser versions of Minecraft (such as Eaglercraft) that fit in a single tiny HTML file are easily accessible. Students can download it once and keep it on their device or a USB drive. After that, it’s one click away, and teachers spend valuable instructional time redirecting students instead of teaching.
Securly Classroom’s September 2026 release solves this problem with a new setting that blocks local HTML files from running.
Why web filtering misses these games
Content filters work by evaluating web traffic. A game opened from a file:// path loads from the student’s own device, so it never touches the network. The same approach works for offline copies of any other HTML games that circulate among students.
The files spread through shared drives, email attachments, and flash drives. A filter policy’s blocked URL list can’t keep up with local files that have no URL.
How the setting works
When the setting is on, Securly Classroom checks every browser tab for local HTML files. If a student opens one, Classroom redirects that tab to a block page. It also employs some other logic to catch more unconventional attempts to open files in the browser. Enforcement continues outside active class sessions, so the block stays in place all day.
Where to find it
Go to Settings > System > Classroom options > Block local HTML files from running. The setting is on by default, so Chromebooks running the current Securly Classroom extension are already blocking local HTML games. It applies across your whole district rather than per teacher or per class.
How to bring this functionality to your district
If your district doesn’t use Securly Classroom yet, you likely don’t have a way to block games that students run from local files. Classroom closes that gap as soon as it’s deployed. Teachers also get a live view of student screens and can implement their own per-class block and allow lists for websites and Windows/macOS apps, so students stay on task and instructional time isn’t wasted.
Learn more about Securly Classroom and see how it can save your district instructional time today.