Project Launch: Building an Offline-First PWA Barcode Sorter
When performing utility fieldwork or managing warehouse logistics, efficiency is everything. Manual data entry or wrestling with heavy native scanning apps that lose data the second you enter a signal dead-zone isn't optimal. I needed a tool that was instant, robust, and completely operational without network connection.
To solve this, I built Meter Scanner: a lightweight, offline-first Progressive Web App (PWA) designed to scan hardware serial numbers via barcodes, automatically sort them by utility type, and instantly export the dataset as a flat text file.
Why It's Built Differently
In alignment with the core vanilla architectural philosophy of this website, this application completely bypasses heavy modern frameworks or massive dependencies. It leverages high-performance browser capabilities to do the heavy lifting:
- Native BarcodeDetector API: Instead of bundling heavy third-party JavaScript scanning engines, the app routes camera frames directly into Android's underlying system ML Kit via Google Chrome. This ensures lightning-fast processing speeds and drastically lower battery drain.
- Total Offline Independence: Driven by a custom Service Worker, all layout components, configurations, and styles are cached locally upon your very first visit. Once added to your device, it requires 0% internet access—perfect for basements or remote tracking sites.
- Intelligent Sorter Gates: Serial strings are systematically filtered at the camera loop level. Barcodes starting with 'G' automatically pop into the Gas index, while codes beginning with 'E' slide into Elektra, completely rejecting structural duplicates and warning against unidentifiable codes via haptic vibration patterns.
- 100% Client-Side Privacy: Your data belongs to you. Collected session logs sync
seamlessly through
localStorageto survive accidental window closes, but not a single byte is ever transmitted to an external server. Data export is generated locally via native JS Blobs.
Launch and Installation
The production app is deployed as an isolated PWA subfolder right on this domain and is completely tracking-free. You can try out the application directly at the link below:
Note: For the best native experience on mobile devices, open the scanner link inside Android Chrome and interact with the custom installation banner, or navigate to Chrome's menu and select "Install app" to save it permanently to your home screen!
Has this utility saved you hours of tedious transcribing or helped optimize your inventory flow? If you find this software helpful and want to support continued feature updates and ad-free maintenance, feel free to securely back the project via a coffee on my Ko-fi link.