The latest articles on DEV Community by Patel Devansh (@pda-dp-shop). https://dev.to/pda-dp-shop https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3854030%2F6df468e7-fbd1-4e72-bcd3-a5599ce488ad.jpeg https://dev.to/pda-dp-shop en Patel Devansh Tue, 31 Mar 2026 18:25:29 +0000 https://dev.to/pda-dp-shop/how-i-built-a-privacy-first-offline-pwa-expense-tracker-3kob https://dev.to/pda-dp-shop/how-i-built-a-privacy-first-offline-pwa-expense-tracker-3kob <h2> What is Spendly? </h2> <p>Spendly is an offline-first expense tracker PWA I built. <br> No server. No cloud. Everything stays on your device.</p> <h2> Why I Built It </h2> <p>Most expense apps send your data to their servers.<br> I wanted something that works 100% offline with real encryption.</p> <h2> Tech Stack </h2> <ul> <li>React + Vite (frontend)</li> <li>TailwindCSS (styling)</li> <li>Dexie.js (local IndexedDB)</li> <li>AES-256-GCM encryption</li> <li>WebAuthn (fingerprint/PIN lock)</li> </ul> <h2> Cool Features </h2> <p><strong>3 Ways to Add Expenses:</strong></p> <ul> <li>Manual keypad entry</li> <li>Barcode scan (Open Food Facts API)</li> <li>Bill photo scan (Tesseract.js OCR)</li> </ul> <p><strong>Security:</strong></p> <ul> <li>AES-256-GCM encryption</li> <li>PBKDF2 with 600,000 iterations</li> <li>Zero data sent to any server</li> </ul> <h2> Live Demo </h2> <p>👉 spendly-24hrs.pages.dev</p> <h2> GitHub </h2> <p>👉 github.com/PDA-DP-Shop/spendly</p> <p>Drop a ⭐ if you find it useful!</p> webdev react javascript privacy