layout before it becomes fully interactive.

For a more detailed look at different techniques and concepts surrounding SSR, please check out this

You can easily prepare an app for server-side rendering using the [Angular CLI](guide/glossary#cli).

The CLI schematic `@nguniversal/express-engine` performs the required steps, as described below.

You can go from the Dashboard to the Heroes page and back.

You can click a hero on the Dashboard page to display its Details page.

* Clicking a hero on the Heroes page does nothing.

* You can't add or delete a hero.

* The search box on the Dashboard page is ignored.

* The *Back* and *Save* buttons on the Details page don't work.

User events other than `routerLink` clicks aren't supported.

The transition from the server-rendered app to the client app happens quickly on a development machine, but you should

always test your apps in real-world scenarios.

There are three main reasons to create a Universal version of your app.

1. Improve performance on mobile and low-powered devices

{@a seo}

{@a web-crawlers}

Angular Universal can generate a static version of your app that is easily searchable, linkable, and navigable without JavaScript.

Universal also makes a site preview available since each URL returns a fully rendered page.

{@a no-javascript}

import {Request} from 'express';

import {REQUEST} from '@nguniversal/express-engine/tokens';

export class UniversalInterceptor implements HttpInterceptor {

constructor(@Optional() @Inject(REQUEST) protected request: Request) {}