# Cloud Sync > Your data syncs automatically across devices. Works offline and catches up when you're back online. Source: https://spentrip.app/help/cloud-sync ## Always in Sync, Even Offline Spentrip syncs your data across all your devices in real time using Firestore. Add an expense on your phone and it appears on your tablet instantly. Lose connectivity and everything keeps working -- the app catches up automatically when you're back online. Cloud sync is a free feature. Every Spentrip account gets it. --> ## Real-Time Sync ### Your Data Receipts, tags, and settings sync automatically across all devices signed into your account. Changes appear instantly. ### Shared Trips Data in shared trips broadcasts to all members in real time. When a teammate adds an expense, everyone sees it immediately. ## Offline Support No internet? No problem. You can create and edit receipts offline. Spentrip stores everything locally and uploads it when connectivity returns. ### Upload Queue When you create receipts offline, they enter an upload queue. The app automatically retries failed uploads with exponential backoff -- no manual intervention needed in most cases. Pending Waiting to upload Uploading Transfer in progress Done Successfully synced Failed Manual retry available ## Receipt File Storage When you scan a receipt or attach a file, the image or PDF is uploaded to cloud storage. Thumbnails are generated and cached locally for fast browsing. ### Supported File Types JPG JPEG PNG GIF WebP PDF ## Security & Backup - **Authentication** -- all data access is protected by Firebase Authentication. Only you (and your trip members) can access your data. - **Encrypted transfer** -- all data travels over encrypted connections. Nothing is sent in plain text. - **Automatic backup** -- your data is automatically backed up via Firestore. No manual exports or backup steps needed. ## Related Articles [Account Settings Manage your profile, sign-in method, and subscription.](/help/account-settings.md) [Receipt Scanning Scan receipts and PDFs that sync to the cloud automatically.](/help/receipt-scanning.md)