🚀 Live Web App: https://midnightlogic.github.io/tokilink/
TokiLink™ for Seiko is an unofficial, high-precision Progressive Web App (PWA) that unifies and controls all Bluetooth-enabled Seiko digital, multi-sound, and NexTime clocks directly from your web browser.
Using modern Web Bluetooth, TokiLink™ replaces multiple proprietary, region-locked mobile apps with a single, elegant, privacy-first web application that runs on Android, Windows, macOS, ChromeOS, Linux, and iOS.
Note
Legal Disclaimer: TokiLink™ for Seiko is an independent, open-source community project. It is not affiliated with, endorsed by, or sponsored by Seiko Group Corporation, Seiko Clock Inc., or any of their subsidiaries. All product names, trademarks, and model identifiers belong to their respective owners and are used strictly for hardware compatibility and identification under nominative fair use.
TokiLink™ unifies models across all official Seiko clock apps into one universal application:
| Series | Supported Models | Key Capabilities & Features |
|---|---|---|
| Multi-Sound Clocks (Onkyo Speaker Series) | SS501A / SS501K (Wide) SS201W / SS201K (Upright) |
• Atomic Time Sync • Multi-Schedule Dual Alarms (Melody / FM Radio, Volume, Snooze) • FM Radio Tuner (76.0–108.0 MHz) & 5 Customizable Station Presets • 5-Level Display Brightness & 4-Level Bass Boost • Sleep Relaxation Timer & Auto Power-Off |
| Series C3 (Gradient Color LED Series) | DL308K (DL308 Series) | • Atomic NTP Time Synchronization • World Timezone Offset Slider (UTC−12 to UTC+14) • Custom Datetime Calibration |
| Standard Digital (SQ Series) | SQ820W / SQ820K SQ821W / SQ821K |
• Atomic NTP Time Synchronization • World Timezone Offset Slider (UTC−12 to UTC+14) • Custom Datetime Calibration |
| NexTime Series (Hybrid Multi-Sync Clocks) | ZS450S (Digital Wall/Desk) ZS451S (Wall + Calendar/Temp/Humidity) ZS250S / ZS250W ZS251S / ZS251W ZS252S / ZS252W / ZS252B ZS253S / ZS253W ZS254S, ZS255W, ZS256B QHB201SM / QHB201WM |
• Atomic NTP Time Synchronization • World Timezone Offset Slider (UTC−12 to UTC+14) • Custom Datetime Calibration |
- One-Click Instant Sync: Calibrate your clock to the exact millisecond in seconds.
- NTP Network Latency Compensation: Pre-fetches atomic UTC time and calculates round-trip time (RTT) offsets before transmitting to the clock for laboratory-grade precision.
- Adaptive UI: Automatically focuses on the clean Time sync screen for digital clocks while seamlessly revealing audio and radio controls when a Multi-Sound model is connected.
- Interactive Global Slider: Smoothly adjust your clock's time across UTC−12:00 to UTC+14:00 with live city landmarks (e.g., Tokyo, London, New York, Sydney).
- Stepper Buttons & Home Reset: Quick
+and−stepping for rapid timezone jumps with a single-tap reset to your local home time. - Custom Datetime Input: Manually specify exact dates and times for testing, daylight saving verification, or custom offsets.
- Dual Independent Alarms: Configure Alarm 1 and Alarm 2 with distinct wake-up times and recurrence.
- Day-of-Week Scheduling: Select specific active days (Monday through Sunday) with quick presets for Weekdays or Weekends.
- Wake-Up Sound Selection: Choose between pleasant onboard chime melodies or wake up to your favorite FM radio preset.
- Volume & Snooze Controls: Customize wake-up volume (levels 1–30) and toggle 5-minute snooze repetition.
- Full Band Coverage: Tune across the entire 76.0 MHz to 108.0 MHz FM band.
- Precision Stepper & Seek: Step up/down by 0.1 MHz or use auto-seek to find local broadcasting channels.
- 5 Customizable Station Presets: Store your favorite radio stations with personalized station names and instant one-tap recall.
- Master Volume Control: Adjust radio listening volume smoothly from 0 to 30.
- 5-Level Display Brightness: Dim the clock display for night-time bedside use or brighten it for sunlit rooms.
- 4-Level Bass Boost: Enhance audio richness and low-end depth for Onkyo speaker output.
- Sleep & Relaxation Timer: Set a countdown timer (15, 30, 60, 90, or 120 minutes) with soothing audio playback before automatic shutdown.
- Auto Power-Off: Save power with configurable inactivity standby timers.
- Installable Desktop & Mobile App: Add TokiLink™ to your Home Screen or Desktop as a standalone app with full offline caching via Service Workers.
- Automatic In-App Update Notifications: Seamlessly alerts you when a new version or feature update is available with 1-click reload.
- Vibrant Dark & Light Modes: Beautiful frosted glass cards, glowing plasma sync button, and dynamic visual state indicators.
- 6 Supported Languages: Fully localized in:
- 🇺🇸 English (
en) - 🇯🇵 Japanese (
ja) - 🇫🇷 French (
fr) - 🇪🇸 Spanish (
es) - 🇩🇪 German (
de) - 🇨🇳 Simplified Chinese (
zh)
- 🇺🇸 English (
Web Bluetooth (navigator.bluetooth) requires a secure HTTPS connection and browser support:
| Platform | Recommended Browsers | Compatibility | Notes |
|---|---|---|---|
| Android | Chrome, Edge, Samsung Internet, Opera | ✅ Full Support | Native Web Bluetooth & 1-click PWA install |
| Android — Brave | Brave Browser | Enable brave://flags/#brave-web-bluetooth-api and Relaunch |
|
| Windows / macOS / Linux / ChromeOS | Chrome, Edge, Opera | ✅ Full Support | Native Web Bluetooth (Tip: enable #enable-web-bluetooth-new-permissions-backend for 1-click zero-dialog sync) |
| Windows / macOS / Linux — Brave | Brave Browser | Enable brave://flags/#brave-web-bluetooth-api and Relaunch |
|
| iOS (iPhone / iPad) — Native Safari | Beacio Safari Extension | ✅ Supported in Safari + PWA | Web Bluetooth extension for Safari. Supports Share → Add to Home Screen to install as a standalone PWA! |
| iOS (iPhone / iPad) — Dedicated App | Bluefy Browser | ✅ Supported via App | Dedicated Web Bluetooth browser from the App Store. Ready out-of-the-box. |
Tip
Using on iPhone / iPad:
- Option 1 (Fastest Setup — Dedicated Browser): Install Bluefy Browser from the App Store. TokiLink™ will launch and sync immediately.
- Option 2 (Home Screen PWA App): Install the free Beacio Extension from the App Store, enable it in Settings → Safari → Extensions, then open TokiLink™ in Safari and tap Share → Add to Home Screen!
Tip
Using on Brave Browser (Desktop & Android): Brave blocks Web Bluetooth by default. To enable:
- Paste
brave://flags/#brave-web-bluetooth-apiinto the address bar and set to Enabled. - (Recommended) Set Use the new permissions backend for Web Bluetooth (
#enable-web-bluetooth-new-permissions-backend) to Enabled. - Click Relaunch.
- Node.js (v18 or higher)
- A Web Bluetooth compatible browser (Google Chrome, Microsoft Edge, Opera, or Samsung Internet)
# 1. Clone the repository
git clone https://github.com/midnightlogic/tokilink.git
cd tokilink
# 2. Install dependencies
npm install
# 3. Start local development server
npm run dev# Start Vite dev server with Cloudflare HTTPS Tunnel
npm run tunnel
# Start Production Bundle with Cloudflare Tunnel (for testing true offline PWA install)
npm run tunnel:prod# Build optimized production bundle
npm run build:fast
# Preview production build locally
npm run preview- 100% Client-Side Execution: All Bluetooth communication and time computations take place entirely within your browser sandbox.
- Zero Tracking / No Analytics: No personal data, device identifiers, or MAC addresses are ever collected or sent to external servers.
- Open-Source Transparency: Complete source code is openly audited and available on GitHub under the Apache 2.0 License.
- Software License: Apache License, Version 2.0. Copyright © 2026 MidnightLogic.
- Trademark Notice: TokiLink™ is a trademark of MidnightLogic. Seiko®, Series C3, NexTime, and model designations (SS501, SS201, DL308, SQ820, SQ821, ZS450, ZS451, ZS250..ZS256) are registered trademarks of Seiko Group Corporation / Seiko Clock Inc. This software is an independent third-party implementation.