Alarm Reminder

WHAT IT DOES

Alarm Reminder is a browser extension that lets you set alarms and reminders that trigger at a specified time. You can set a time (hour and minute) and an optional message, and the tool displays a live countdown showing how much time remains until the alarm triggers. When the alarm goes off, it plays a sound notification and displays a visual alert. You can snooze the alarm for 5 minutes or dismiss it entirely. Multiple alarms can be set simultaneously, and all alarms persist globally—even after page reloads or browser restarts. The tool is ideal for anyone who needs time-based reminders, such as work breaks, meeting alerts, cooking timers, or medication reminders.

WHERE IT RUNS

Alarm Reminder runs on any webpage, overlaying a floating panel that does not interfere with page content. It operates entirely in your browser as a lightweight userscript, using JavaScript's Date object for time calculations and the Web Audio API for sound generation. It works on any page, whether static or dynamic, with no external dependencies. All alarm data is stored locally using GM_setValue—no data is ever sent to any server.

HOW TO USE

After installation, open the floating panel by clicking the extension icon. To set an alarm, enter the time in HH:MM format (24-hour) in the "Time" field, optionally add a message, and click "Set". You can also use the quick-set buttons (+5m, +15m, +30m, +1h) to set an alarm for a specific amount of time from now. The panel displays a list of all active alarms with their times and countdown timers. When an alarm triggers, it appears highlighted in red with a 🔔 icon, plays a sound, and displays a notification. Click "Snooze (5m)" to postpone the alarm by 5 minutes, or "Dismiss" to stop it. Click "Delete" to remove an alarm permanently. Alarms are saved automatically and persist across page loads—if you set an alarm and close the page, it will still trigger when you return.

REAL MECHANISM — WHY THIS WORKS

Most browser alarms rely on setTimeout or setInterval with a fixed delay, which can drift or fail when the tab is backgrounded. Alarm Reminder uses a different approach: it stores alarms as persistent data objects with hours and minutes, and checks them every 10 seconds against the current time. The check calculates the time until each alarm using: if the alarm time is earlier than now, it's scheduled for the next day. The countdown display is recalculated on each check. When an alarm is triggered, the tool plays a sound using the Web Audio API, generating a series of sine wave tones at increasing frequencies (523Hz, 659Hz, 784Hz, 1046Hz) for a pleasant chime-like alarm. Snooze works by advancing the alarm time by 5 minutes and resetting the triggered flag, effectively rescheduling the alarm. The tool also uses GM_notification to display a system notification when available. This approach ensures reliable, persistent, and fully private alarm functionality without requiring any external services or network access.

THE PANEL

The floating panel is fully draggable and remembers its position per site, snapping to the edges of the viewport when dragged near them. You can collapse the panel to a small icon to minimize screen distraction and expand it back with a single click. The panel is resizable from the bottom-right corner, giving you more space to view alarms and controls. Press the Escape key to close the panel instantly. The panel remains open across page navigation within the same domain, maintaining your current view state. All preferences—panel position and all alarm data—are saved globally for a seamless experience.

PLEASE NOTE

Alarm Reminder requires the free BotGentz extension to be installed and enabled, as it relies on the cross-extension messaging API provided by BotGentz for DOM access permissions. Alarms are checked every 10 seconds; this may be less precise than system alarms but is sufficient for reminders. Sound generation uses the Web Audio API and may require user interaction on some browsers to initialize. System notifications using GM_notification may require additional permissions. All alarm data is stored locally in your browser using GM_setValue. No alarm times, messages, or usage data are ever sent to any server. The extension does not read, store, or transmit any personal information. It only stores and triggers alarms locally at your request.