One click, and thirty screens land in the same place.

Classcastle is a teacher web app paired with a lightweight browser extension for students. You run the room from any browser; they join with a code. When it's time for the task, you press one button, and every student's browser opens the same page — no reading URLs off the whiteboard, no lost kids.

Free for teachers. Works on Chromebooks. No student accounts needed.

Windows
macOS
ChromeOS
Linux

30 students, one command: go to microbit.org

How a lesson runs

Set up once, then it disappears into the background of your teaching.

01

You open a room in the teacher app

No install for you — it runs in any browser. Start a room and you get a short code to put on the board.

02

Students join with the extension

A small add-on for Chrome or Edge, installed once. Students type in your room code and light up green in your teacher view.

03

You press go, everyone arrives

Type the page once — microbit.org, a quiz, a shared doc — and every joined browser navigates there together, instantly.

Built for the realities of a classroom

Lightweight by design

No heavy install, no login walls. It runs quietly and doesn't slow down ageing school machines.

One room, full visibility

See who's joined and where their browser currently is, at a glance, from your own screen.

Works with what you already use

Send students to any URL — a site, a form, a game, a shared document. If it's a webpage, Classcastle can send them there.

For IT: rolling it out across a fleet

You don't need every student clicking install one by one. Push the extension centrally and it's ready before the first lesson.

01

Get the extension ID

Find Classcastle's ID and store listing under Admin → Deployment in the teacher app. You'll use this ID in your policy.

02

Force-install through policy

Add it to ExtensionInstallForcelist in the Google Admin console for ChromeOS and Chrome, or push it via Intune or GPO for Edge. No end-user action required.

03

Allow the connection

Safelist Classcastle's domain in your web filter or firewall so room connections aren't blocked on the school network.

04

Verify on a test device

Confirm the icon appears pinned and can join a test room, then roll out to the rest of the fleet with the same policy.

Stop saying "did everyone find the page?"