The Ultimate Free Offline School Bell System for Sri Lankan Schools (2026 Edition)

Is your school still relying on a manual bell? In the fast-paced educational environment of 2026, timing is everything. Missing a period bell by even two minutes can disrupt the flow of the entire day.

At School ICT, we understand that not every school has a stable internet connection or the budget for expensive automation hardware. That is why we developed the School ICT Bell System (Version 5.3)—a completely free, browser-based tool that works 100% offline.

Designed by Mr. Ruwan Suraweera, this tool brings digital precision to your daily routine, handling everything from the Morning Gatha to the final dismissal, automatically.

2. Windows Settings (Must Do!)

Because this runs in Chrome, Windows will try to sleep the computer or the hard drive after 30 minutes. You must disable this:

1. Open Start Menu -> Type “Sleep” -> Select “Power & sleep settings”.
2. Under Sleep, change “When plugged in, PC goes to sleep after” to Never.

3. Chrome Settings (Must Do!)

Chrome also sleeps tabs to save memory. You must turn this off for the bell system:

1. Open Chrome Settings (3 dots -> Settings).
2. Go to Performance.
3. Turn Memory Saver OFF, or click “Add” next to “Always keep these sites active” and add the URL of your bell system file.

2. Firefox Specific Settings (Prevent Tab Discarding)

Firefox tries to save memory by unloading tabs you haven’t looked at in a while. Since this bell system runs all day, we need to stop that.

1. Open Firefox and type about:config in the address bar.
2. Click “Accept the Risk and Continue”.
3. Search for: dom.min_background_timeout_value
4. CRITICAL: Search for browser.tabs.unloadOnLowMemory

3. Optional: Firefox Performance Settings

If you still have issues, you can disable Firefox’s automatic performance throttling:

1. Go to Settings (3 lines menu -> Settings).
2. Scroll down to the Performance section.
3. Uncheck “Use recommended performance settings”.

guide to setting this up on Q4OS Linux.

2. Best Browser for Q4OS (i386)

Q4OS usually comes with Konqueror, Chromium, or allows you to install Firefox.

• Recommendation: Use Chromium or Firefox (ESR 32-bit).
• Why? They support the “Web Worker” (Heartbeat Engine) code I wrote to prevent the clock from stopping. Older browsers might not support this.

3. How to Run & “Install” on Q4OS

Since this is an offline file, you don’t need to install a server (like Apache/XAMPP).

1. Transfer Files: Copy your folder (containing index.html and Sound_Files) to the /home/user/Documents/BellSystem/ folder on your Linux machine.
2. Test It:

4. IMPORTANT: Prevent Sleep on Q4OS (Trinity Desktop)

Q4OS uses the Trinity Desktop Environment (TDE) or Plasma. By default, it will turn off the screen or suspend the CPU to save power, which stops the bell. You must disable this.

If using Trinity (TDE):

1. Open the Start Menu -> Control Panel.
2. Go to System Administration -> Monitor & Display.
3. Look for “Energy Saving” or “DPMS”.
4. Uncheck “Enable Display Power Management” (or set all timers to “0” or “Never”).
5. Go to Power Control (if available in Control Panel) and ensure “Suspend” or “Sleep” is set to Never.

5. How to Auto-Start on Boot (Kiosk Mode)

If this computer is dedicated to the bell system, you want it to open automatically when you turn the PC on.

1. Open the file manager and go to: /home/YOUR_USERNAME/.trinity/Autostart/ (Note: You might need to enable “Show Hidden Files” to see .trinity)
2. Right-click in empty space -> Create New -> Text File.
3. Name it bell.desktop.
4. Paste this code inside:

Why Choose This Bell System? (Key Benefits)

Unlike complex software that requires monthly fees or heavy installation, our system is lightweight and user-friendly.

1. Works 100% Offline

Once downloaded, this system does not require the internet. It runs locally on your computer using any modern web browser (Google Chrome, Edge, or Firefox). This makes it perfect for schools in rural areas with limited connectivity.

2. Fully Customizable Schedule

Every school is different. Whether you need a special assembly on Mondays or a shorter interval on Fridays, the system supports 7 distinct day profiles (Monday–Friday, Samithi, and Special days).

3. Audio Integration

It’s not just a “beep.” The system is pre-loaded to play essential audio files:

• Morning Routine: Buddhist Gathas, National Anthem, School Song.
• Announcements: “Teacher’s Period Start,” “Interval,” “Hodama Lamaya” selection.
• Emergency: Special alarm buttons for emergencies.

4. User-Friendly Interface

Designed with the School ICT colors (Deep Blue & Alert Red), the interface is clean and professional. It features:

• Large Green Play Buttons: For manual control.
• Small Red Stop Buttons: To instantly silence audio.
• Live Clock: Displays the current time and full date (e.g., “Monday, January 01”).

How It Works: Online vs. Offline

A common question we get is: “Is this a website?”

The Answer: It relies on web technology (HTML/JavaScript), but it functions like a desktop application.

• Browser-Based: You open it like a website.
• Local Storage: All files (sounds and code) sit on your hard drive.
• Zero Lag: Because it doesn’t need to “load” from the internet, the bells ring at the exact second, every time.

Step-by-Step Guide: How to Install & Use

Follow these simple instructions to set up the system in your computer lab or main office.

Step 1: Download the Package

Click the link below to download the full system (includes the App and the Sound_Files folder).

• File Format: .RAR or .ZIP
• Size: Lightweight (<50MB with audio).

Step 2: Extract the Files

You cannot run the system from inside the ZIP file.

1. Right-click the downloaded file.
2. Select “Extract Here” or “Extract to Folder”.
3. You will see a folder containing school bell System.html and a folder named Sound_Files.

Step 3: Launch the System

Double-click the bel.html file. It will open in your default web browser.

• Note: Allow the browser permission to play audio if asked.

How to Edit the Time Schedule

To ensure stability and prevent accidental changes by students, the interface is in Protected Mode. You cannot change the times by simply clicking on the screen.

To change the Bell Times permanently:

1. Close the browser.
2. Open the folder where you extracted the files.
3. Open the folder.
4. Right-click on the file named schedule.js.
5. Select Open with > Notepad.
6. You will see lines like this:
7. JavaScript{ time: "07:30:00", name: "School Start", sound: "School_Start.mp3", active: true },
8. Edit the Time: Change "07:30:00" to your desired time (24-hour format).
9. Save the file (File > Save) and close Notepad.
10. Open School Bell System.html again. Your new times are now active!

Download Now

Ready to automate your school? Get the latest online version tool below. (Off Line download Link Inside)

[Open Tool ] (Link to: https://schoolict.net/bell-system-rar)

Frequently Asked Questions (FAQ)

Q: Can I change the mp3 sounds? A: Yes! Put your new MP3 file into the Sound_Files folder. Then, open schedule.js and change the filename in the code to match your new file (e.g., change "School_Start.mp3" to "My_New_Sound.mp3").

Q: Why can’t I right-click on the app? A: The app is in “Protected Mode” to prevent students or unauthorized users from viewing the source code or messing with the layout during school hours.

Q: Does the computer need to stay on? A: Yes. For the auto-bell to ring, the computer must be powered on and the bel.html tab must remain open.

Need Help? If you have issues customizing the code, contact the admin at rmssd2000@yahoo.com.