How I Built a Fast, Offline-First Gluten Detection PWA Using Web OCR & Open Food Facts

Description and use

Glutensa is a lightweight PWA that quickly and offline determines gluten presence in foods using barcode scanning and OCR, with local caching and fallback to Open Food Facts.

Problem

Consumers with gluten restrictions need instant, reliable ingredient information at the grocery store, but existing apps are slow or heavy.

Outcome

The app delivers fast, offline-first gluten detection with a local cache and seamless API fallback, improving user experience for dietary restrictions.

Workflow

• Scan product barcode or capture label image
• Check local cached dataset for product info
• If not found, query Open Food Facts API
• Parse returned data and display gluten status
• Cache result locally for future use

Evidence

We first check an optimized local/cached dataset. If no match is found, the app seamlessly falls back to querying the Open Food Facts API

Source