Search Engine Optimization is very important, as our application must be easy to find on the internet. In terms of Angular and React, when we consider SEO we must look back to the fundamental differences in how these technologies are built: ReactJS implements server-side rendering, while AngularJS 1.x is almost fully rendered directly in the browser.
It’s much easier to set up server-side rendering with React than with Angular – and server-side rendering is better for SEO. Therefore, Angular requires additional tools to implement SEO best practices. PhantomJS is a well-known library to address SEO issues in AngularJS; it helps us set up an application so it gives a search engine prerendered HTML in-full, while the user receives usual output from the application. But this demands additional coding: web developers must create an additional AngularJS module for SEO and set up PhantomJS to present an HTML snapshot to the search engine. Many other tools similar to PhantomJS take the same approach.
To put it simply, both the ReactJS library and the AngularJS framework allow us to make a single page application SEO-friendly, but AngularJS demands more effort to achieve that goal. Additionally, it’s sometimes difficult to make an AngularJS app 100% SEO-friendly even when we do use PhantomJS or a similar tool. Admittedly, the SEO situation with Angular should become much better when Angular 2 is officially released. This latest edition of the AngularJS framework takes after React, offering server-side rendering to better overcome SEO issues related to SPA development.