What are Web Storages?
What is Web Storage and why is it needed?
In browser applications, there is often a need to store data without immediately sending it to the server. For this purpose, various storage methods exist, collectively referred to as Web Storage mechanisms. These allow data to be stored on the user's device, providing speed, convenience, and in some cases, offline functionality.
Through JavaScript, it is possible to store the user's selected language, theme (e.g., dark or light mode), the last visited page, session state, or even a complete offline database. However, which storage method to use depends on the nature of the data and its intended purpose.
1. Cookies
2. LocalStorage
3. SessionStorage
4. IndexedDB
5. Cache Storage (with Service Workers)
6. File System Access API (only in some browsers)
Each of these methods is designed for different scenarios—small or large data, temporary sessions, or even full offline application implementation.
Persistent storage methods (e.g., LocalStorage, IndexedDB) retain data even after the browser is closed.
Temporary storage methods (e.g., SessionStorage, memory-based storage) retain data only during the current session.
Here is a brief comparison of when and for what purpose you can use different storage methods.
- Cookies → Auth, tracking, server-side access
- LocalStorage → Light client-side settings
- SessionStorage → Data stored during a session (e.g., form steps)
- IndexedDB → Large, structured data (offline apps)
- Cache Storage → Assets/API cache (with Service Worker)
- File System API → File editing or download/save functionality
Data storage in the browser is a crucial tool for modern web applications. Choosing the right method depends on the amount of data, storage duration, and security requirements. In the next article, we will discuss the oldest and most common method: Cookies.