Have you ever had a user submit a form, lose their internet connection, and watch their request fail?
I wanted to solve this problem in Angular without forcing developers to build their own queue, IndexedDB storage, retry logic, and network synchronization.
So I built ngx-offline-sync — an open-source Angular library for offline-first HTTP request synchronization.
How it works
When the application is online, requests work normally through Angular's HttpClient.
When the connection is lost:
HTTP Request
↓
Offline
↓
Queue
↓
IndexedDB
The request is persisted locally instead of simply being lost.
Once the connection comes back:
IndexedDB
↓
Sync
↓
HTTP Request
↓
Completed
What it currently supports
- Automatic queuing of
POST,PUT,PATCH, andDELETErequests - IndexedDB persistence
- Automatic synchronization after reconnect
- Retry handling
- Request status tracking
- Parallel queue processing with
batchSize - Angular HTTP interceptor integration
- No additional dependencies required
The goal is to keep the API simple — you continue using Angular's HttpClient as usual.
Example
provideOfflineSync({
batchSize: 5,
});
That's it. The library handles the queue and synchronization infrastructure for you.
The project is still evolving, and I'm working on improving the API, documentation, testing, and network-state handling.
If you're working with Angular and building applications where network interruptions are a real possibility, I'd love for you to take a look.
