What is server side rendering SSR in Vue?

Server-side rendering (SSR) in Vue improves performance and SEO by generating HTML on the server. 1. The server runs Vue app code and generates HTML based on the current route. 2. That HTML is sent to the browser immediately. 3. Vue hydrates the page, attaching event listeners to make it interactive. This results in faster first-load performance, better SEO, and improved UX for slow networks. However, SSR has trade-offs like more complex setup, higher server load, and limited browser API access. To implement SSR, use Vue Server Renderer with a Node.js server or frameworks like Nuxt.js. SSR may not be ideal if your app is used by logged-in users, doesn’t rely on SEO, has high dynamic content, or you're on a tight budget or timeline, in which case static site generation or client-side rendering might be better alternatives.

Server-side rendering (SSR) in Vue means generating the HTML of your Vue app on the server instead of in the browser. This helps with performance and SEO because the user gets a fully rendered page right away, without waiting for JavaScript to load and execute.

How SSR Works in Vue

In a regular Vue app (client-side rendered), the browser downloads a minimal HTML file and a bundle of JavaScript. Once that JS runs, the app starts and the content is rendered.

With SSR:

• The server runs the Vue app code and generates the HTML based on the current route.
• That HTML is sent to the browser immediately.
• Then, Vue "hydrates" the page — attaches event listeners and makes it interactive.

This results in faster first-load performance and better SEO since crawlers get real HTML content.

Why Use SSR in Vue?

There are a few main reasons why you'd want to go with SSR:

• Better SEO: Search engines can index your content more easily.
• Faster initial load: Users see content sooner because the HTML comes pre-rendered.
• Improved UX for slow networks: Less time waiting for JavaScript to download and run.

However, SSR also has trade-offs like more complex setup, higher server load, and limited browser API access during rendering.

Setting Up SSR in Vue

To implement SSR, you typically use Vue Server Renderer along with a Node.js server. Here's a simplified flow:

• Create a Vue app using createApp.
• On the server, use renderToString from vue-server-renderer to generate HTML.
• Send that HTML to the client.
• Include the same Vue app code in your client bundle so Vue can take over after loading.

You can also use frameworks like Nuxt.js, which simplifies SSR by abstracting most of the configuration.

A basic example:

// server.js
const express = require('express');
const { createBundleRenderer } = require('vue-server-renderer');
const renderer = createBundleRenderer(serverBundle, { template });

app.get('*', (req, res) => {
  renderer.renderToString({ url: req.url }, (err, html) => {
    if (err) return res.status(500).end();
    res.end(html);
  });
});

When Not to Use SSR

SSR isn't always the best choice. If your app:

• Is mostly used by logged-in users
• Doesn’t rely on SEO
• Has high dynamic content
• You're on a tight budget or timeline

Then you might be better off with static site generation (like with Vite VuePress or Nuxt generate) or plain client-side rendering.

That’s the core idea behind SSR in Vue — it’s powerful when you need fast, SEO-friendly pages but adds complexity compared to simpler rendering methods.

The above is the detailed content of What is server side rendering SSR in Vue?. For more information, please follow other related articles on the PHP Chinese website!