You can use following technologies to save data on the client side in ASP.NET –
• Web Storage: It simply provides a key-value mapping, e.g. localStorage["name"] = username; Unfortunately, present implementations only support string-to-string mappings, so you need to serialize and de-serialize other data structures. You can do so using JSON.stringify() and JSON.parse().
• Web SQL Database: It gives you all the power and effort of a structured SQL relational database.
• Indexed Database: It is somewhere in between Web Storage and Web SQL Database. Like Web Storage, it's a straightforward key-value mapping, but it supports indexes like those of relational databases, so searching objects matching a particular field is fast; you don't have to manually iterate through every object in the store.
• File Access: It is an API for reading file content in JavaScript. Given a set of files the user has added to a "file" input element, you can read the content of the file or reference it as a URL, for example, if the user has specified an image file, you can show the image.