Storing data on the client
Web applications have the ability to save data to/in the browser.
Available tools
Example usage
- Web Storage
- Non-sensitive information
- Application settings
- Application state changes for offline usage
- Cookies
- Session or user information that may change the server's respose
- IndexedDB
- Store large amounts of data in object storage stores that can be queried with optimiztions for reading/writing
Comparison
| Session Storage | Local Storage | Cookies | |
|---|---|---|---|
| Deleted when browser data is cleared | ✅ | ✅ | ✅ |
| Can be modified outside of your application | ✅ | ✅ | ✅ |
| Deleted when browser is closed | ✅ | ||
| Sent with every web request | ✅ |
Caveats
Persistance: We can not always guarantee that data stored on the client (in the browser) will persist. Users are in control of clearing browser caches and data stores.
Security: Local storage and cookie data can be easily read by anyone using a web brower's development tools. There are no restrictions preventing third part scripts from accessing local storage or cookies as well.
Guarantees: The lack of persistance and security means that we should not assume integrity of data stored in the client.