Isomorphic JavaScript


Isomorphic JavaScript, also known as Universal JavaScript, describes JavaScript applications which run both on the client and the server.

Mechanism

Isomorphic JavaScript works in the context of a single-page application. In a typical SPA, most of the application logic, including routing, is encapsulated in a bundled JavaScript file that is sent to the client. While this frees up the server, as it does not have to handle so many requests, it also makes the initial load slow for the client, as the entire application needs to be sent over to the client.
With Isomorphic JavaScript, when a client web page is first requested from the server, the view of the page is generated on the server, similar to server-side dynamic web pages, and sent over to the client. The client can then render the view immediately. After the initial view is rendered, the complete SPA is downloaded in the background, and subsequent actions are handled client-side.

Name

The naming of the term 'Isomorphic JavaScript' has been a matter of controversy. The term 'isomorphic' was first coined by Charlie Robbins from Nodejitsu, in one of the company's blog posts. Spike Brehm, a software engineer from Airbnb, wrote another blog post using the same term. However, others have proposed to use the term Universal JavaScript instead.

Benefits

There have been several isomorphic JavaScript frameworks and libraries created, most notably Meteor and React. Others includes , , , , , and .