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15 starsTypeScript

Manage Casio G-Shock watches from the browser

by izivkov·May 2, 2026·3 points·0 comments
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AI Analysis

●●●BangerNiche GemZero to One

Web Bluetooth API brings G-Shock management to browsers, bypassing the official Android app.

Strengths
  • •Web Bluetooth API enables zero-install access to watch BLE protocols directly from browser
  • •Per-model capability detection handles 19+ G-Shock variants with different feature sets
  • •Atomic-clock NTP sync with manual pairing gesture respects browser security constraints
Weaknesses
  • •No iOS Safari support requires third-party browsers like Bluefy or WebBLE
  • •Cannot auto-sync in background due to browser gesture requirements for BLE connections
Category
Hardware
Target Audience

G-Shock watch owners, hardware enthusiasts

Similar To

G-Shock Move app · Casio Watch+ app

Post Description

I've been maintaining GShockSmartSync (Android) for a while, and a recurring ask was "can I do this without installing an app?" So I built a browser-based version using the Web Bluetooth API.

What it does: - Time sync with NTP (atomic-clock precision) - Full alarm management (all 5 alarms) - Reminders/events with labels - Watch settings (illumination, sound, display) - Battery level monitoring - Zero install, zero accounts — all BLE traffic stays local between your browser and the watch

Tech: Next.js + TypeScript, Web Bluetooth API, Material Design 3. Supports 19+ G-Shock models with per-model capability detection.

Live demo: https://gshock.avmedia.org Source: https://github.com/izivkov/gshock-smart-sync-webapp

Can be self-hosted on a Raspberry Pi or any Node-capable server.

Browser support: Chrome/Edge/Opera (desktop & Android). iOS needs Bluefy or WebBLE. Safari and Firefox don't support Web Bluetooth — that's a vendor decision, not a fixable limitation on my end.

One honest limitation: Web Bluetooth requires an explicit user gesture to initiate a connection, so there's no background auto-sync — you click "Pair Watch" each session. Fine for my use case, but worth knowing upfront.

The most interesting part was reverse-engineering the BLE protocol. Happy to go into detail on that if anyone's curious.

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