By now, you may have observed that cookies and local storage serve almost completely different purposes. The only thing they have in common is that they store data. The following is a brief comparison of cookies and local storage:
Cookies | Local storage |
Cookies are transferred to a server on every request automatically by the browser | To transfer local storage data to a server, you need to manually send an Ajax request or send it through hidden form fields |
If data needs to be accessed and read both by the client and server, use cookies | If the data needs to be accessed and read only by the client, use local storage |
Cookies can have an expiration date, after which they are automatically deleted | Local storage provides no such expiration date feature; it can only be cleared by JavaScript |
The maximum size of a cookie is 4 KB | The maximum size of local storage depends on the browser and platform, but it is usually around 5 MB per domain |